Obstentrics_Williams

Obstentrics_Williams. For labor aumentation, results of a randomized controlled trial showed oral misoprostol, 75 ILg given at 4-hour intervals for a maximum of two doses, to be safe and efective (Bleich, 2011). he 75-Lg dose was based on a previous dose-inding study (Villano, 2011). Although there was more uterine tachy systole among women with labor augmented with misoprostol, the frequency of nonreassuring fetal status or cesarean delivery did not difer between oxytocin and misoprostol.


Obstentrics_Williams

Obstentrics_Williams. In many instances, preinduction cervical ripening and labor induction are simply a continuum. hus, "ripening" can also stimulate labor. If not, induction or augmentation may be continued with solutions of oxytocin given by infusion pump. Its use in augmentation is a key component in the active management oflabor, described in Chapter 22 (p. 438). With oxytocin use, the American College of Obstetricians and Gynecologists (2016) recommends fetal heart rate and uterine contraction monitoring. Contractions can be monitored either by palpation or by electronic means.


Obstentrics_Williams

Obstentrics_Williams. he goal of induction or augmentation is to efect uterine activity suicient to produce cervical change and fetal descent, while avoiding development of a nonreassuring fetal status. In general, oxytocin is discontinued if the number of contractions persists with a frequency of more than ive in a 10-minute period or more than seven in a 15-minute period or with a persistent nonreassuring fetal heart rate pattern. Oxytocin discontinuation nearly always rapidly lowers contraction frequency. When oxytocin is stopped, its concentration in plasma rapidly falls because the half-life is approximately 3 to 5 minutes. Seitchik and associates (1984) found that the uterus contracts within 3 to 5 minutes of beginning an oxytocin infusion and that a plasma steady state is reached in 40 minutes. Response is highly variable and depends on preexisting uterine activity, cervical status, pregnancy duration, and individual biological diferences. Caldeyro-Barcia and Poseiro (1960) reported that the uterine


Obstentrics_Williams

Obstentrics_Williams. is highly variable and depends on preexisting uterine activity, cervical status, pregnancy duration, and individual biological diferences. Caldeyro-Barcia and Poseiro (1960) reported that the uterine response to oxytocin increases from 20 to 30 weeks' gestation and rises rapidly at term (Chap. 24, p. 479).


Obstentrics_Williams

Obstentrics_Williams. Oxytocin Dosage. A 1-mL ampule containing 10 units of oxytocin usually is diluted into 1000 mL of a crystalloid solution and administered by infusion pump. A typical infusate consists of 10 or 20 units, which is 10,000 or 20,000 mU or one or two 1-mL vials, respectively, mixed into 1000 mL oflactated Ringer solution. his mixture results in an oxytocin concentration of 10 or 20 mU/mL, respectively. To avoid bolus administration, the infusion should be inserted into the main intravenous line close to the venipuncture site. Oxytocin is generally very successful when used to stimulate labor. In one large Cochrane metaanalysis, oxytocin was compared with expectant management, and fewer women-8 versus 54 percent-failed to deliver vaginally within 24 hours Induction and Augmentation of Labor 509 TABLE 26-3. Various Low-and High-Dose Oxytocin Regimens Used for Labor Induction


Obstentrics_Williams

Obstentrics_Williams. Induction and Augmentation of Labor 509 TABLE 26-3. Various Low-and High-Dose Oxytocin Regimens Used for Labor Induction Low-dose 0.5-1.5 15-40 2 15 4,8,12,s16,20,25,30 4.5 15-30 4.5 aUterine tachysystole is more common with shorter intervals. bWith uterine tachysystole and after oxytocin infusion is discontinued, It is restarted at one half the previous dose and then increased at 3 mU/min incremental doses. Data from Merrill, 1999; Satin, 1992, 1994; Xenakis, 1995. with oxytocin (Alfirevic, 2009). This analysis studied diferent oxytocin dosing regimens.


Obstentrics_Williams

Obstentrics_Williams. Data from Merrill, 1999; Satin, 1992, 1994; Xenakis, 1995. with oxytocin (Alfirevic, 2009). This analysis studied diferent oxytocin dosing regimens. Oxytocin Regimens. Several evidence-based regimens for labor stimulation are now recommended by the American College of Obstetricians and Gynecologists (2016). hese and others are shown in Table 26-3. Initially, only variations of low-dose protocols were used in the United States. Subsequently, O'Driscoll and colleagues (1984) described their Dublin protocol for the active management of labor that called for oxytocin at a starting dosage of 6 mU/min and advanced in 6-mU/min increments. Subsequent comparative trials during the 1990s studied high-dose (4 to 6 mU/min) versus conventional low-dose (0.5 to 1.5 mU/min) regimens, both for labor induction and for augmentation.


Obstentrics_Williams

Obstentrics_Williams. From Parkland Hospital, Satin and associates (1992) evaluated an oxytocin regimen using an initial and incremental dosage of 6 mU/min compared with one using 1 mU/min. Increases at 20-minute intervals were provided as needed. Among 1112 women undergoing induction, the 6-mU/min regimen resulted in a shorter mean admission-to-delivery time, fewer failed inductions, and no cases of neonatal sepsis. Among 1676 women who had labor augmentation, those who received the 6-mU/min regimen had a shorter duration-to-delivey time, fewer forceps deliveries, fewer cesarean deliveries for dystocia, and lower rates of intrapartum chorioamnionitis or neonatal sepsis. With this protocol, uterine tachysystole was managed by oxytocin discontinuation followed by resumption when indicated and at half the stopping dosage. hereafter, the dosage was increased at 3 mU/min when appropriate, instead of the usual 6-mU/min increase used for women without tachysystole. No adverse neonatal efects were observed.


Obstentrics_Williams

Obstentrics_Williams. Xenakis and coworkers (1995) reported beneits using an incremen tal oxytocin regimen starting at 4 m U / min. In another study, 816 women were randomly assigned for labor induction and 816 for augmentation with incremental oxytocin gihen at either 1.5 or 4.5 mU/min (Merrill, 1999). Women randomized to the 4.5 mU/min dosage had signiicantly shorter mean durations of induction-to-second-stage labor and inductionto-delivery times. Nulliparas randomized to the 4.5 mU/min dosage had a signiicantly lower cesarean delivery rate for dystocia compared with those given 1.5 mU/min dosage-6 versus 12 percent. Thus, benefits favor higher-dose regimens of 4.5 to 6 mU/min compared with lower dosages of 0.5 to 1.5 mU/min.


Obstentrics_Williams

Obstentrics_Williams. In 1990 at Parkland Hospital, routine use of the 6-mU/min oxytocin beginning and incremental dosage was incorporated and continues through today. In other labor units, a 2-mU/min beginning and incremental oxytocin regimen is preferred and administered. With either regimen, dosages are employed for either labor induction or augmentation. Although a Cochrane metaanalysis of randomized and quasi-randomized trials comparing high-dose versus low-dose regimens for labor induction at term reported no benefit of higher dosing, the metaanalysis included studies judged to have high potential bias. The authors concluded that the results might be confounded by these poorquality studies (Budden, 2014).


Obstentrics_Williams

Obstentrics_Williams. Interval between Incremental Dosing. Intervals to increase oxytocin doses vary from 15 to 40 minutes (see Table 26-3). Satin and associates (1994) addressed this aspect with a 6-mU/ min regimen providing increases at either 20-or 40-minute intervals. Women assigned to the 20-minute interval regimen for labor augmentation had a significantly reduced cesarean delivery rate for dystocia compared with that for the 40-minute interval regimen-8 versus 12 percent. As perhaps expected, uterine tachysystole was significantly more frequent with the 20-minute escalation regimen.


Obstentrics_Williams

Obstentrics_Williams. Other investigators reported even more frequent incremental increases. F rigoletto (1995) and Xenakis (1995) and their coworkers gave oxytocin at 4 mU/min with increases as needed every 15 minutes. Merrill and Zlatnik (1999) started with 4.5 mU/min doses and increased this every 30 minutes. L6pez-Zeno and associates (1992) used 6 mU/min doses and 15-minute intervals. Thus, there are several acceptable oxytocin protocols that at least appear dissimilar. But, a comparison of protocols from two institutions indicates that this is not so: 1. The Parkland Hospital protocol uses a starting dose of oxytocin at 6 mU/min, which is increased by 6-mU/min every 40 minutes, and employs flexible dosing based on uterine tachysystole. 2. The University of Alabama at Birmingham Hospital protocol begins oxytocin at 2 mU/min and increases it as needed every 15 minutes to 4,8, 12, 16,i20,25, and 30 mU/min.


Obstentrics_Williams

Obstentrics_Williams. 2. The University of Alabama at Birmingham Hospital protocol begins oxytocin at 2 mU/min and increases it as needed every 15 minutes to 4,8, 12, 16,i20,25, and 30 mU/min. hus, although the regimens at first appear disparate, if there is no uterine activity, either regimen is delivering 12 mU/ min by 45 minutes into the infusion. Maximal OxytOcin Dosage. The maximal efective dose of oxytocin to achieve adequate contractions in all women is diferent. Wen and colleagues (2001) studied 1151 consecutive nulliparas and found that the likelihood of progression to vaginal delivery decreased at and beyond an oxytocin dosage of 36 mU/min. Still, at a dosage of 72 mU/min, half of the nulliparas were delivered vaginally. Thus, if contractions are not adequate-less than 200 Montevideo units-and if the fetal status is reassuring and labor has arrested, an oxytocin infusion dose greater than 48 mU/min has no apparent risks.


Obstentrics_Williams

Obstentrics_Williams. Unless the uterus is scarred, uterine rupture associated with oxytocin infusion is rare, even in parous women. Flannelly and associates (1993) reported no cases of uterine ruptures, with or without oxytocin, in 27,829 nulliparas. here were eight instances of overt uterine rupture during labor in 48,718 parous women. Only one of these was associated with oxytocin use. A population-based retrospective review from Denmark reported a rupture rate of 3.3 per 100,000 women without prior cesarean, with the highest risk among multiparas (This ted, 2015). Our experiences from Parkland Hospital are that oxytocin induction and augmentation are associated with uterine rupture (Happe, 2017). During an 8-year period in which there were about 95,000 births, 15 women sufered a primary uterine rupture, and 14 of these cases were associated with oxytocin use. In half of these women, prostaglandins were also given before augmentation with oxytocin.


Obstentrics_Williams

Obstentrics_Williams. Oxytocin has amino-acid homology similar to arginine vasopressin and has signiicant antidiuretic action. When infused at doses of 20 mU/min or more, renal free water clearance drops markedly. If aqueous luids are infused in appreciable amounts along with oxytocin, water intoxication can lead to convulsions, coma, and even death. In general, if oxytocin is to be administered in high doses for a considerable period of time, its concentration should be increased rather than raising the flow rate of a more dilute solution. Consideration also should be given to use of crystalloids-either normal saline or lactated Ringer solution. Contraction forces in spontaneously laboring women range from 90 to 390 Montevideo units (Chap. 24, p. 479). Caldeyro-Barcia (1950) and Seitchik (1984) with their coworkers found that the mean or median spontaneous uterine contraction pattern between 140 and 150 Montevideo units resulted in progression to vaginal delivery.


Obstentrics_Williams

Obstentrics_Williams. In the management of active-phase arrest, and with no contraindication to intravenous oxytocin, decisions must be made with knowledge of the safe upper range of uterine activity. Hauth and colleagues (1986) described an efective and safe protocol for oxytocin augmentation for active-phase arrest. With it, more than 90 percent of women achieved an average of at least 200 to 225 Montevideo units. They later reported that nearly all women in whom active-phase arrest persisted despite oxytocin generated more than 200 Montevideo units (Hauth, 1991). Importantly, despite no labor progression, no adverse maternal or perinatal efects were noted in those ultimately requiring cesarean delivery. here are no data regarding safety and eicacy of contraction patterns in women with a prior cesarean delivery, with twins, or with an overdistended uterus.


Obstentrics_Williams

Obstentrics_Williams. First-stage arrest of labor is deined as a completed latent phase and contractions exceeding 200 NIontevideo units for more than 2 hours without cervical change. Some have attempted to deine a more accurate duration for active-phase arrest (Spong, 2012). Arulkumaran and coworkers (1987) extended the 2-hour limit to 4 hours and reported a 1.3-percent cesarean delivery rate in women who continued to have adequate con tractions and progressive cervical dilation of at least 1 cm/hr. In another 4 hours of labor, half required cesarean delivery.


Obstentrics_Williams

Obstentrics_Williams. Rouse and colleagues (1999) prospectively managed 542 women at term with active-phase arrest and no other complications. Their protocol was to achieve a sustained pattern of at least 200 Montevideo units for a minimum of 4 hours. This time frame was extended to 6 hours if activity of 200 Montevideo units or greater could not be sustained. Almost 92 percent of these women were delivered vaginally. As discussed in Chapter 23 (p. 443), these and other studies support the practice of allowing an active-phase arrest of 4 hours (Rouse, 2001).


Obstentrics_Williams

Obstentrics_Williams. Zhang and coworkers (2002) analyzed labor duration from 4 cm to complete dilatation in 1329 nulliparas at term. They found that before dilation of 7 cm was reached, lack of progress for more than 2 hours was not uncommon in those who delivered vaginally. Alexander and associates (2002) reported that epidural analgesia prolonged active labor by 1 hour compared with duration of the active phase as deined by Friedman (1955). Consideration of these changes in the management oflabor, especially in nulliparas, may safely reduce the cesarean delivery rate.


Obstentrics_Williams

Obstentrics_Williams. As data have accrued, investigators have increasingly questioned the thresholds for labor arrest disorders established by Friedman and others in the 1960s. In particular, investigators with the Consortium on Sai Labor reported that half of cases of dystocia after labor induction occurred before 6 cm of cervical dilation (Boyle, 2013; Zhang, 2010c). Even for women with spontaneous labor, these researchers found that active-phase labor was more likely to occur at 6 cm, and after slow progress between 4 and 6 cm (Zhang, 2010a). Additionally, they reported that a 2-hour threshold for diagnosing arrest disorders may be too brief when cervical dilation is <6 em (Zhang, 201Ob). This is discussed in detail in Chapter 23 (p. 444). Importantly, however, these studies of data from the Collaborative Perinatal Project included only singleton term gestation with spontaneous onset of labor, vaginal delivery, and a normal perinatal outcome. By excluding abnormal outcomes, cesarean deliveries, and


Obstentrics_Williams

Obstentrics_Williams. Perinatal Project included only singleton term gestation with spontaneous onset of labor, vaginal delivery, and a normal perinatal outcome. By excluding abnormal outcomes, cesarean deliveries, and those who were more than 6 cm dilated upon arrival, the above studies that sought to redeine the labor curve


Obstentrics_Williams

Obstentrics_Williams. Induction and Augmentation of Labor 511 have been faulted for introducing biases that limit general use of these findings (Cohen, 20 15a, b). Elective amniotomy with the intention of accelerating labor is often performed. Shown in Table 26-4, amniotomy at approximately 5-cm dilation accelerated spontaneous labor by 1 to 1 Y2 hours. Importantly, neither the need for oxytocin stimulation nor the overall cesarean delivery rate was increased. Although the incidences of mild and moderate cord compression patterns were raised following amniotomy, cesarean delivery rates for fetal distress were not higher. Most importantly, there were no adverse perinatal efects.


Obstentrics_Williams

Obstentrics_Williams. For labor induction, artificial rupture of the membranessometimes called surgical induction-can be used and always implies a commitment to delivery. The main disadvantage of amniotomy used alone for labor induction is the unpredictable and occasionally long interval until labor onset. hat said, in a randomized trial, Bakos and Backstrom (1987) found that amniotomy alone or combined with oxytocin was superior to oxytocin alone. Mercer and colleagues (1995) randomly assigned 209 women undergoing oxytocin induction to either early amniotomy at 1 to 2 cm or late amniotomy at 5 cm. Early amniotomy was associated with a 4-hour reduction in labor duration. With early amniotomy, however, the incidence of chorioamnionitis was elevated.


Obstentrics_Williams

Obstentrics_Williams. For labor augmentation, amniotomy is commonly performed when labor is abnormally slow. Rouse and associates (1994) found that amniotomy with oxytocin augmentation for arrested active-phase labor shortened the time to delivery by 44 minutes compared with that of oxytocin alone. Although amniotomy did not alter the delivery route, one drawback was that it significantly increased the incidence of chorioamnionitis. Regardless of the indication, amniotomy is associated with a risk of cord prolapse. To minimize this risk, disengagement of the fetal head during amniotomy is avoided. Toward this goal, fundal or suprapubic pressure or both may be helpful. Some clinicians prefer to rupture membranes during a contraction. If the vertex is not well applied to the lower uterine segment, aNo effect on overall rate; cesarean delivery for fetal distress significantly increased. blncreased mild and moderate umbilical cord compression patterns. NA = not assessed.


Obstentrics_Williams

Obstentrics_Williams. NA = not assessed. a gradual egress of amnionic fluid can sometimes be accomplished by several membrane punctures with a 26-gauge needle held with a ring forceps and with direct visualization using a vaginal speculum. In many of these, however, membranes tear and luid is lost rapidly. Because of the risk of cord prolapse or rarely abruption, the fetal heart rate is assessed before and immediately after amniotomy.


Obstentrics_Williams

Obstentrics_Williams. Labor induction by membrane "stripping" is a frequent practice. Several studies have suggested that membrane stripping is safe and lowers the incidence of postterm pregnancy without consistently raising the incidence of ruptured membranes, infection, or bleeding. Authors of one large metaanalysis found that membrane stripping reduced the number of women remaining undelivered after 41 weeks without elevating the infection risk. They concluded that eight women would need to undergo membrane stripping to avoid one labor induction. Downsides are discomfort and associated bleeding (Boulvain, 2005). Alexander ]M, Sharma SK, McIntire 0, et al: Epidural analgesia lengthens the Friedman active phase oflabor. Obstet Gynecol 100(1):46,o2002 Alirevic Z, Maifel N, Weeks A: Oral misoprostol for induction of labour. Cochrane Database Syst Rev 6:CD001338 2014


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Obstentrics_Williams. Alirevic Z, Maifel N, Weeks A: Oral misoprostol for induction of labour. Cochrane Database Syst Rev 6:CD001338 2014 Alirevic Z, Kelly A], Dowswell T: Intravenous oxytocin alone for cervical ripening and induction of labour. Cochrane Database Syst Rev 4:CD003246, 2009 American Academy of Pediatrics, American College of Obstetricians and Gynecologists: Guidelines for Perinatal Care, 8th ed. Elk Grove Village, P, 2017 American College of Obstetricians and Gynecologists: Induction of labor. Practice Bulletin No. 107, August 2009, Reairmed 2016 American College of Obstetricians and Gynecologists: Intrapartum fetal heart rate monitoring: nomenclature, interpretation, and general management principles. Practice Bulletin No. 106,o] uly 2009, Reairmed 20o17 a American College of Obstetricians and Gynecologists: Vaginal birth after previous cesarean delivery. Practice Bulletin 115, August 2010, Reairmed 20 17b


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Obstentrics_Williams. American College of Obstetricians and Gynecologists: Vaginal birth after previous cesarean delivery. Practice Bulletin 115, August 2010, Reairmed 20 17b Amorosa ]M, Stoneo], Factor SH, et al: A randomized trial of Foley bulb for labor induction in premature rupture of membranes in nulliparas (FLIP). Am] Obstet GynecoI217(3):360.e1


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Obstentrics_Williams. Arulkumaran S, Koh CH, Ingemarsson I, et al: Augmentation of labourmode of delivery related to cervi metric progress. Aust N Z ] Obstet GynaecoIo27:304, 1987 Bailit ]L, Gregory KD, Reddy UM, et al: Maternal and neonatal outcomes by labor onset type and gestational age. Am ] Obstet Gynecol 202(3):245. el,o2010 Bakos 0, Backstrom T: Induction of labor: a prospective, randomized study into amniotomy and oxytocin as induction methods in a total unselected population. Acta Obstet Gynecol Scand 66:537, 1987 Bateman BT, Mhyre ]M, Callaghan WM, et al: Peripartum hysterectomy in the United States: nationwide 14 year experience. Amo] Obstet Gynecol 206(1):63.el,o2012 Bishop EH: Pelvic scoring for elective induction. Obstet GynecoIo24:266, 1964 Bleich AT, Villano KS, Lo ]Y, et al: Oral misoprostol for labor augmentation: a randomized controlled trial. Obstet GynecoIo118(6):1255, 2011 Boulvain M, Kelly A, Irion 0: Intracervical prostaglandins for induction of labour. Cochrane Database Syst Rev


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Obstentrics_Williams. for labor augmentation: a randomized controlled trial. Obstet GynecoIo118(6):1255, 2011 Boulvain M, Kelly A, Irion 0: Intracervical prostaglandins for induction of labour. Cochrane Database Syst Rev 1:CD006971, 2008 Boulvain M, Stan C, Irion 0: Membrane sweeping for induction of labour. Cochrane Database Syst Rev 1 :CD00045o1, 2005 Boyle A, Reddy UM, Landy H], et al: Primary cesarean delivery in the United States. Obstet GynecoIo122(1):33, 2013 Budden A, Chen L], Henry A: High-dose versus low-dose oxytocin infusion regimens for induction of labour at term. Cochrane Database Syst Rev 10:CD009701,o2014 Bullarbo M, Orrskog ME, Andersch B, et al: Outpatient vaginal administration of the nitric oxide donor isosorbide mononitrate for cervical ripening and labor induction postterm: a randomized controlled study. Amo] Obstet GynecoIo196:50.e1,o2007


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Obstentrics_Williams. Caldeyro-Barcia R, Alvarez H, Reynolds SR: A better understanding of uterine contractility through simultaneous recording with an internal and a seven channel external method. Surg Obstet Gynecol 91 :641, 1950 Caldeyro-Barcia R, Poseiro JJ: Physiology of the uterine contraction. Clin Obstet Gynecol 3:386, 1960 Carbone ]F, Tuuli MG, Fogertey P], et al: Combination of Foley bulb and vaginal misoprostol compared with vaginal misoprostol alone for cervical ripening and labor induction: a randomized controlled trial. Obstet Gynecol. 121:247,2013 Chanrachakul B, Herabutya Y, Punyavachira P: Potential eicacy of nitric oxide for cervical ripening in pregnancy at term. Int ] Gynaecol Obstet ,2000 Chiossi G, Lai Y, Landon MB, et al: Timing of delivery and adverse outcomes in term singleton repeat cesarean deliveries. Obstet Gynecol 121 (3) :561, 2013


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Obstentrics_Williams. Clark SL, Miller DO, Belfort MA, et al: Neonatal and maternal outcomes associated with elective term delivery. Amo] Obstet Gynecol 200(2): 156. el,o2009 Cohen WR, Friedman EA: Misguided guidelines for managing labor. Am ] Obstet GynecoIo212(6):753.e1, 2015a Cohen R, Friedman A: Perils of the new labor management guidelines. Am ] Obstet Gynecolo212(4):420, 2015b Connolly A, Kohari KS, Rekawek P, et al: A randomized trial of Foley balloon induction oflabor trial in nulliparas (FIAT-N). Am] Obstet Gynecol. 215:392.el,2016 Cullen M: Important drug warning concerning unapproved use of intravaginal or oral misoprostol in pregnant women for induction of labor or abortion. 2000. Available at: http://www.fda.gov/ohrms/dockets/dailys/OO/ NovOO/111500/cpOOO1.pdf. Accessed July 28,o2017 Dahlen HM, McCullough ]M, Fertig AR, et al: Texas Medicaid payment reform: fewer early elective deliveries and increased gestational age and birthweight. Health ff(Millwood) 36(3):460, 20o17


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Obstentrics_Williams. Dahlen HM, McCullough ]M, Fertig AR, et al: Texas Medicaid payment reform: fewer early elective deliveries and increased gestational age and birthweight. Health ff(Millwood) 36(3):460, 20o17 Darney BG, Snowden ]M, Cheng W, et al: Elective induction of labor at term compared with expectant management: maternal and neonatal outcomes. Obstet GynecoIo122:761, 2013 Dobert M, Brandsetter A, Heinrich W, et al: he misoprostol vaginal insert compared with oral misoprostol for labor induction in term pregnancies: a pair-matched case-control study. ] Perinatal Med June 26, 20o17 [Epub ahead of print] Ekerhovd E, Bullarbo M, Andersch B, et al: Vaginal administration of the nitric oxide donor isosorbide mononitrate for cervical ripening at term: a randomized controlled study. Amo] Obstet GynecoIo189:o1692, 2003


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Obstentrics_Williams. Ekerhovd E, Weijdegard B, Brannstrom I, et al: Nitric oxide induced cervical ripening in the human: involvement of cyclic guanosine monophosphate, prostaglandin F2a, and prostaglandin E2• Amo] Obstet GynecoIo186:745, 2002 Feltovich H: Cevical evaluation. From ancient medicine to precision medi cine. Obstet GynecoIo130:51, 2017 Fisch ]M, English 0, Pedaline S, et al: Labor induction process improvement: a patient quality-of-care initiative. Obstet Gynecol 113(4):797,o2009 Flannelly GM, Turner M], Rassmussen M], et al: Rupture of the uterus in Dublin: an update.o] Obstet GynaecoIo13:440, 1993 Fraser W, Marcoux S, Moutquin ]M, et al: Efect of early amniotomy on the risk of dystocia in nulliparous women. N Engl] Med 328:1145, 1993 Friedman A: Primigravid labor: a graphicostatistical analysis. Obstet Gynecol 6:567, 1955 Frigoletto FD, Lieberman E, Lang ]M, et al: A clinical trial of active management oflabor. N Engl] Med 333:745, 1995


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Obstentrics_Williams. Frigoletto FD, Lieberman E, Lang ]M, et al: A clinical trial of active management oflabor. N Engl] Med 333:745, 1995 Fruhman G, Gavard ]A, Amon E, et al: Tension compared to no tension on a Foley trans cevical catheter for cervical ripening: a randomized controlled trial. Am] Obstet GynecoI216:67.e1, 2017 Garite T], Porto M, Carlson N], et al: he inluence of elective amniotomy on fetal heart rate patterns and the course of labor in term patients: a randomized study. Am] Obstet GynecoIo168:1827, 1993


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Obstentrics_Williams. Ghosh A, Lattey R, Kelly A]: Nitric oxide donors for cervical ripening and induction of labour. Cochrane Database Syst Rev 12:CD00690 1, 2016 Gibson KS, Waters TP: Measures of success: prediction of successful labor induction. Semin PerinatoIo39:475, 2015 Happe SK, Yule CS, Wells CE: Outcomes in pregnancies complicated by intrapartum uterine rupture. Unpublished data, 2017 Hatield AS, Sanchez-Ramos L, Kaunitz M: Sonographic cervical assessment to predict the success of labor induction: a systematic review with metaanalysis. Amo] Obstet Gynecol 197: 186, 2007 Hauth]C, Hankins GO, Gilstrap LC III: Uterine contraction pressures achieved in parturients with active phase arrest. Obstet Gynecol 78:344, 1991 Hauth ]c, Hankins GO, Gilstrap LC III: Uterine contraction pressures with oxytocin induction/augmentation. Obstet GynecoIo68:305, 1986 Hawkins ]S, Stephenson M, Powers B, et al: Diabetes mellitus: an independent predictor of duration of prostaglandin labor induction. ] Perinatol 37:488,


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Obstentrics_Williams. Obstet GynecoIo68:305, 1986 Hawkins ]S, Stephenson M, Powers B, et al: Diabetes mellitus: an independent predictor of duration of prostaglandin labor induction. ] Perinatol 37:488, 20o17


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Obstentrics_Williams. Hawkins ]S, Wing DA: Current pharmacotherapy options for labor induction. Expert Opin Pharmacother 13(14):2005,2012 Hernandez ]S, Wendel GO ]r, Sheield]S: Trends in emergency peripartum hysterectomy at a single institution: 1988-2009. Amr] PerinatoIr30(5):365, 2013 Hofman MK, Sciscione AC: Elective induction with cervical ripening increases the risk of cesarean delivery in multiparous women. Obstet GynecoIr101:7S, 2003 Hofmeyr G], G.ilmezoglu M, Pileggi C: Vaginal misoprostol for cervical ripening and induction of labour. Cochrane Database Syst Rev 1 0:CD000941 , 2010 Ivars J, Garabedian C, Devos P, et al: Simpliied Bishop score including parity predicts successful induction of labor. Eur ] Obstet Gynecol Reprod Bioi 203:309,r2016 Jozwiak M, Bloemenkamp KW, Kelly AJ, et al: Mechanical methods for induction of labour. Cochrane Database Syst Rev 3:CD001233, 2012


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Obstentrics_Williams. Jozwiak M, Bloemenkamp KW, Kelly AJ, et al: Mechanical methods for induction of labour. Cochrane Database Syst Rev 3:CD001233, 2012 Jozwiak M, Oude Rengerink K, Benthem M, et al: Foley catheter versus vaginal prostaglandin E2 gel for induction of labour at term (PROBAAT trial): an open-label, randomised controlled trial. Lancet 378(9809):2095,r201r1 Jozwiak M, Oude Rengerink K, Ten Eikelder ML, et al: Foley catheter or prostaglandin E2 inserts for induction of labour at term: an open-label randomized controlled trial (PROBAAT-P trial) and systematic review of literature. Eur J Obstet Gynecol Reprod Bioi 170(1):137, 2013 Jozwiak M, Ten Eikelder M, Rengerink KO, et al: Foley catheter versus vaginal misoprostol: randomized controlled trial (PROBAAT-M Study) and systematic review and meta-analysis of literature. Am J Perinatol 31: 145, 2014


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Obstentrics_Williams. Karjane NW, Brock EL, Walsh SW: Induction of labor using a Foley balloon, with and without extra-amniotic saline infusion. Obstet Gynecol 107:234, 2006 Kawakita T, Reddy UM, Iqbal SN, et al: Duration of oxytocin and rupture of membranes before diagnosing a failed induction of labor. Obstet Gynecol 128:373,r2016 Kominiarek A, Zhang J, Vanveldhuisen P, et al: Contemporaty labor patterns: the impact of maternal body mass index. Am J Obstet Gynecol 205(3):244.e1,r2011 Landon MB, Hauth JC, Leveno KJ, et al: Maternal and perinatal outcomes associated with a trial of labor ater prior cesarean delivery. N Engl J Med 351(25):2581,r2004 Laughon SK, Branch OW, Beaverr], et al: Changes in labor patterns over 50 years. Am J Obstet GynecoI206(5):419.e1, 2012 Laughon SK, Zhang J, Troendle ], et al: Using a simplified Bishop score to predict vaginal delivery. Obstet GynecoIr117(4):805, 2011


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Obstentrics_Williams. Laughon SK, Zhang J, Troendle ], et al: Using a simplified Bishop score to predict vaginal delivery. Obstet GynecoIr117(4):805, 2011 Levine LD, Downes L, Elovitz A, et al: Mechanical and pharmacologic methods of labor induction: a randomized controlled trial. Obstet Gynecol 128:1357,r2016 Little SE, Caughey AB: Induction of labor and cesarean: what is the true relationship? Clin Obstet Gynecol 58:269, 2015 Lo JY, Alexander JM, McIntire DO, et al: Ruptured membranes at term: randomized, double-blind trial of oral misoprostol for labor induction. Obstet Gynecolr101:685,r2003 Lopez-Zeno JA, Peaceman M, Adashek ]A, et al: A controlled trial of a program for the active management oflabor. N Engl J Med 326:450, 1992 Luthy DA, Malmgren ]A, Zingheim RW: Cesarean delivery after elective induction in nulliparous women: the phYSician efect. Amr] Obstet Gynecol 191:1511,r2004 Macones GA: Elective induction of labor: waking the sleeping dogma? Ann Intern Med 151 (4):281, 2009


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Obstentrics_Williams. Macones GA: Elective induction of labor: waking the sleeping dogma? Ann Intern Med 151 (4):281, 2009 Maier JT, Metz M, Watermann N, et al: Induction of labor in patients with an unfavorable cervix after a cesarean using an osmotic dilator versus vaginal prostaglandin. J Perinatal Med June 26, 2017 [Epub ahead of print] Martin JA, Hamilton BE, Osterman MJ, et al: Births: final data for 2015. Natl Vital Stat Rep 66(1):1, 2017 Maslow AS, Sweeny AL: Elective induction of labor as a risk factor for cesarean delivery among low-risk women at term. Obstet GynecoIr95:917, 2000 McMaster K, Sanchez-Ramos L, Kaunitz M: Evaluation of a trans cevical Foley catheter as a source of infection: a systematic review and meta-analysis. Obstet GynecoIr126:539, 2015 Mei-Dan E, Walisch A, Valencia C, et al: Making cervical ripening EASI: a prospective controlled comparison of single versus double balloon catheters. J Matern Fetal Neonatal Med 27:1765,r2014


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Obstentrics_Williams. Mei-Dan E, Walisch A, Valencia C, et al: Making cervical ripening EASI: a prospective controlled comparison of single versus double balloon catheters. J Matern Fetal Neonatal Med 27:1765,r2014 Melamed N, Ray JG, Geary M, et al: Induction of labor before 40 weeks is associated with lower rate of cesarean delivery in women with gestational diabetes mellitus. Am J Obstet GynecoI214:364, 2016 Mercer BM, McNanley T, O'Brien JM, et al: Early versus late amniotomy for labor induction: a randomized trial. Am J Obstet Gynecol 173: 1371, 1995 Merrill DC, Zlatnik FJ: Randomized, double-masked comparison of oxytocin dosage in induction and augmentation of labor. Obstet Gynecol 94:455, 1999 Induction and Augmentation of Labor 513 Miller NR, Cypher L, Foglia LM, et al: Elective induction oflabor compared with expectant management of nulliparous women at 39 weeks of gestation: a randomized controlled trial. Obstet GynecoIr126:1258, 2015


Obstentrics_Williams

Obstentrics_Williams. National Institutes of Health: ClinicaITrials.gov: a randomized trial of induction versus expectant management (ARRIVE). 2015. Available at: https:!1 c1inicaltrials.gov/ct2/show/NCT01990612. Accessed July 28,r2017 O'Driscoll K, Foley M, MacDonald 0: Active management of labor as an alternative to cesarean section for dystocia. Obstet Gynecol 63:485, 1984 Oshiro BT, Kowalewski L, Sappenfield W, et al: A multistate quality improvement program to decrease elective deliveries before 39 weeks of gestation. Obstet Gynecol 121(5):1025,r2013 Raghuraman N, Stout MJ, Young OM: Utility of the simpliied Bishop score in spontaneous labor. Am ] Perinatol 33: 1176, 2016


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Obstentrics_Williams. Raghuraman N, Stout MJ, Young OM: Utility of the simpliied Bishop score in spontaneous labor. Am ] Perinatol 33: 1176, 2016 Roland e, Warshak CR, DeFranco EA: Success of labor induction for preeclampsia at preterm and term gestational ages. J Perinatol 37(6):636, 2017 Rooney Thompson M, Towers CV, Howard Be, et l: The use of prostaglandin El in peripartum patients with asthma. m J Obstet Gynecol 212:392.e 1, 2015 Rouse 0], McCullough e, Wren AL, et al: Active-phase labor arrest: a randomized trial of chorioamnion management. Obstet GynecoIr83:937, 1994 Rouse OJ, Owen J, Hauth J C: Active-phase labor arrest: oxytocin augmenta tion for at least 4 hours. Obstet Gynecol 93:323, 1999 Rouse OJ, Owen J, Hauth JC: Criteria for failed labor induction: prospective evaluation of a standardized protocol. Obstet Gynecol 96:671, 2000 Rouse OJ, Owen J, Savage KG, et al: Active phase labor arrest: revisiting the 2-hour minimum. Obstet Gynecol 98:550, 2001


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Obstentrics_Williams. Rouse OJ, Owen J, Savage KG, et al: Active phase labor arrest: revisiting the 2-hour minimum. Obstet Gynecol 98:550, 2001 Saccone G, Berghella V: Induction of labor at full term in uncomplicated singleton gestations: a systematic review and metaanalysis of randomized controlled trials. Am J Obstet GynecoIr213:629, 2015 Salemi ]L, Pathak EB, Salihu HM: Infant outcomes ater elective early-term delivery compared with expectant management. Obstet Gynecol 127:657, 2016 Satin AJ, Leveno KJ, Sherman ML, et al: High-dose oxytocin: 20-versus 40-minute dosage interval. Obstet Gynecol 83:234, 1994 Satin A], Leveno KJ, Sherman ML, et al: High-versus low-dose oxytocin for labor stimulation. Obstet Gynecol 80: 111, 1992 Schoen CN, Grant G, Berghella V, et al: Intracevical Foley catheter with and without oxytocin for labor induction: a randomized controlled trial. Obstet GynecoIr129:1046,r2017


Obstentrics_Williams

Obstentrics_Williams. Schoen CN, Grant G, Berghella V, et al: Intracevical Foley catheter with and without oxytocin for labor induction: a randomized controlled trial. Obstet GynecoIr129:1046,r2017 Seitchik J, Amico J, Robinson AG, et al: Oxytocin augmentation of dysfunctional labor. IV. Oxytocin pharmacokinetics. Am J Obstet Gynecol 150:225, 1984 Sievert A, Kuper SG, Jauk VC: Predictors of vaginal delivery in medically indicated early preterm induction oflabor. Am J Obstet GynecoIr217(3):375.e1 Simon CE, Grobman WA: When has an induction failed? Obstet Gynecol 105:705,r2005 Smith M, Hofman MK, Sciscione A: Elective induction oflabor in nulliparous women increases the risk of cesarean delivery. Obstet Gynecolr101:45S, 2003 Snowden JM, Muoto I, Darney BG, et al: Oregon's hard-stop policy limiting elective early-term deliveries: association with obstetric procedure use and health outcomes. Obstet GynecoIr128:1389, 2016


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Obstentrics_Williams. Snowden JM, Muoto I, Darney BG, et al: Oregon's hard-stop policy limiting elective early-term deliveries: association with obstetric procedure use and health outcomes. Obstet GynecoIr128:1389, 2016 Spong CY, Berghella V, Wenstrom KD, et al: Preventing the first cesarean delivery. Summary of a Joint Eunice Kennedy Shriver National Institute of Child Health and Human Development, Sociery for Maternal-Fetal Medicine, and American College of Obstetricians and Gynecologists Workshop. Obstet GynecoIr120(5):1181, 2012


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Obstentrics_Williams. Ten Eikelder ML, Oude Rengerink K, Jozwiak M, et al: Induction of labor at term with oral misoprostol versus a Foley catheter (PROBAAT-II): a multicenter randomized controlled non-inferioriry trial. Lancet 387:1619,r2016 histed DL, Mortensen LH, Krebs L. Uterine rupture without previous caesarean delivery: a population-based cohort study. Eur J Obstet Gynecol Reprod BioI. 195:151,r2015 homas J, Fairclough A, Kavanagh J, et al: Vaginal prostaglandin (PGE2 and PGF2a) for induction of labour at term. Cochrane Database SYSt Rev 6:CD003101,r2014 Thorbiornson A, Vladic T, Stjernholm V: Oral versus vaginal prostaglandin for labor induction. J Matern Fetal Neonatal Med 30:789,r2017 Tita AT, Landon MB, Spong CY, et al: Timing of elective repeat cesarean delivery at term and neonatal outcomes. N Engl J Med 360(2):111,r2009 Towers CV, Briggs GG, Rojas JA: he use of prostaglandin E2 in pregnant patients with asthma. Am J Obstet GynecoIr190(6):1777, 2004


Obstentrics_Williams

Obstentrics_Williams. UK Amniotomy Group: A multicentre randomised trial of amniotomy in spontaneous first labour at term. BJOG 101:307, 1994 Vaisanen-Tommiska M, Nuutila M, Aittomaki K, et al: Nitric oxide metabolites in cervical fluid during pregnancy: further evidence for the role of cevical nitric oxide in cervical ripening. Am J Obstet Gynecol 188:779, 2003 Vaisanen-Tommiska M, Nuutila M, Ylikorkala 0: Cervical nitric oxide release in women posnerm. Obstet Gynecol 103:657,r2004 Verhoeven Cj, Opmeer BC, Oei SG, et al: Transvaginal sonographic assessment of cervical length and wedging for predicting outcome of labor induction at term: a systematic review and meta-analysis. Ultrasound Obstet Gynecol. 42:500, 2013 Villano KS, Lo jY, Alexander jM: A dose-finding study of oral misoprostol for labor augmentation. Am j Obstet Gynecol 204(6):560.el, 2011 Wagner M: Of-label use of misoprostol in obstetrics: a cautionary tale. BjOG 112: 266,r2005


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Obstentrics_Williams. Wagner M: Of-label use of misoprostol in obstetrics: a cautionary tale. BjOG 112: 266,r2005 Weeks AD, Fiala C, Safar P: Misoprostol and the debate over of-label drug use. BjOG 112: 269, 2005 Wen T, Beceir A, Xenakis E, et al: Is there a maximum efective dose of Pitocin? Am j Obstet Gynecol 185:5212,r2001 Williams JW: Obstetrics: a Text-book for the Use of Students and Practitioners. New York, o. Appleton and Co., 1903 Wing OA, Brown R, Plante A, et al: Misoprostol vaginal insert and time to vaginal delivery. A randomized controlled trial. Obstet Gynecolrl22(2 pt 1): 201, 2013 Wolfe H, Timofeev j, Tefera E, et al: Risk of cesarean in obese nulliparous women with unfavorable cervix: elective induction vs expectant management at term. Am j Obstet Gynecol. 211:53.e1, 2014 Xenakis EM, Langer 0, Piper jM, et al: Low-dose versus high-dose oxytocin augmentation of labor-a randomized trial. m j Obstet Gynecol 3: 1874, 1995


Obstentrics_Williams

Obstentrics_Williams. Xenakis EM, Langer 0, Piper jM, et al: Low-dose versus high-dose oxytocin augmentation of labor-a randomized trial. m j Obstet Gynecol 3: 1874, 1995 Yeast jO, Jones A, Poskin M: Induction of labor and the relationship to cesarean delivery: a review of 001 consecutive inductions. Am j Obstet Gynecol 180:628, 1999 Zhang j, Landy Hj, Branch OW, et al: Contemporary patterns of spontaneous labor with normal neonatal outcomes. Obstet Gynecol 116(6): 1281, 20 lOa Zhang j, Troendle j, Mikolajczyk R, et al: The natural history of the normal irst stage of labor. Obstet Gynecol 115 (4): 705, 201 Ob Zhang j, Troendle j, Reddy UM, et al: Contemporary cesarean delivery practice in the United States. Am j Obstet Gynecol 203(4):326.el, 20lOc Zhang j, Troendle jF, Yancey MK: Reassessing the labor curve in nulliparous women. Am j Obstet Gynecol 187:824,r2002


Obstentrics_Williams

Obstentrics_Williams. As soon as the head appears at the vulva the physician should be ready to restrain its progress. He should hold his hand in such a manner as to be able to bring it immediatey into action, or in many instances the resistance of the vulva is unexpectedy overcome, and a single pain may be suicient to push the head suddeny through it with a resulting perineal tea. -J. hitridge Williams (1903)


Obstentrics_Williams

Obstentrics_Williams. -J. hitridge Williams (1903) As described by Williams, the natural culmination of secondstage labor is controlled vaginal delivery of a healthy neonate with minimal trauma to the mother. Vaginal delivery is the preferred route of delivery for most fetuses, although various clinical settings may favor cesarean delivery. Of delivery routes, spontaneous vaginal vertex delivery poses the lowest risk of most maternal comorbidity, and comparisons with cesarean delivery are found in Chapter 30 (p. 568). Delivery is usually spontaneous, although some maternal or fetal complications may warrant operative vaginal delivery, described in Chapter 29 (p. 553). Last, a malpresenting fetus or multifetal gestation in many cases may be delivered vaginally but requires special techniques. These are described in Chapters 28 (p. 543) and 45 (p. 888).


Obstentrics_Williams

Obstentrics_Williams. he end of second-stage labor is heralded as the perineum begins to distend, the overlying skin becomes stretched, and the fetal scalp is seen through the separating labia. Increased perineal pressure from the fetal head creates reflexive bearing-down eforts, which are encouraged when appropriate. At this time, preparations are made for delivery. If the bladder is distended, catheterization may be necessary. Continued attention is also given to fetal heart rate monitoring. s one example, a nuchal cord oten tightens with descent and may lead to deepening variable decelerations.


Obstentrics_Williams

Obstentrics_Williams. During second-stage labor, pushing positions may vary. But for delivery, the dorsal lithotomy position is most common and often the most satisfactory. For better exposure, leg holders or stirrups are used. Corton and associates (2012) found no increased rates of perineal lacerations with or without their use. With positioning, legs are not separated too widely or placed one higher than the other. Within the leg holder, the popliteal region should rest comfortably in the proximal portion and the heel in the distal portion. he legs are not strapped into the stirrups, thereby allowing quick flexion of the thighs backward onto the abdomen should shoulder dystocia develop. Legs may cramp during second-stage pushing, and cramping is relieved by repositioning the afected leg or by brief massage.


Obstentrics_Williams

Obstentrics_Williams. Preparation for delivery includes vulvar and perineal cleansing. If desired, sterile drapes may be placed in such a way that only the immediate area around the vulva is exposed. Scrubbing, gowning, gloving, and donning protective mask and eyewear protect both the laboring woman and accoucheur from infectious agents. • Delivery of the Head By the time of perineal distention, the position of the occiput is usually known. In some cases, however, molding and caput formation may have precluded early accurate identification. At this time, careful assessment is again performed as described in Chapter 22 (p. 426). In most cases, position is directly occiput anterior (OA) or is rotated slightly oblique. But, in perhaps 5 percent, occiput posterior (OP) positioning persists.


Obstentrics_Williams

Obstentrics_Williams. With each contraction, the vulvovaginal opening is dilated by the fetal head to gradually form an ovoid and inally, an almost circular opening (Fig. 27-1). his encirclement of the largest head diameter by the vulvar ring is termed crowning. he perineum thins and may spontaneously lacerate. he anus becomes greatly stretched, and the anterior wall of the rectum can easily be seen through it.


Obstentrics_Williams

Obstentrics_Williams. Routine episiotomy is no longer recommended, and selective use aims to enlarge the vaginal opening for specific indications (p. 529). To limit spontaneous vaginal laceration, some perform antenatal massage of the perineal body to increase perineal distensibility or intrapartum perineal massage to widen the introitus for head passage. During massage with a lubricant, the perineum is grasped in the midline by both hands using the thumb and opposing ingers. Outward and lateral stretching to thin the perineum is repeatedly performed. But in randomized studies, this technique did not significantly prevent perineal laceration (Beckmann, 2013; Mei-dan, 2008; Stamp, 2001). Antepartum use of the Epi-No intravaginal pump balloon has a similar aim, but it also fails to prevent perineal trauma or levator injury (Brito, 2015; Kamisan Atan, 2016).


Obstentrics_Williams

Obstentrics_Williams. When the head distends the vulva and perineum enough to open the vaginal introitus to a diameter of 5 cm or more, a gloved hand may be used to support the perineum (Fig. 27-2). he other hand is used to guide and control the fetal head to deliver the smallest head diameter through the introitus and to FIGURE 27-2 Delivery of the head. The mouth appears over the perineum. avoid expulsive delivery. Slow delivery of the head may decrease lacerations (Laine, 2008). Overall, bracing the perineum lowers rates of anal sphincter injury compared with a "hands of' approach to delivery (Bulchandani, 2015; McCandlish, 1998).


Obstentrics_Williams

Obstentrics_Williams. Alternatively, if expulsive eforts are inadequate or expeditious delivery is needed, the modied Ritgen maneuvermay be employed or an episiotomy cut. With the modified maneuver, gloved ingers beneath a draped towel exert forward pressure on the fetal chin through the perineum just in front of the coccyx. Concurrently, the other hand presses against the occiput (Fig. 27-3). Originally described in 1855, the maneuver allows controlled fetal head delivery (Cunningham, 2008). It also favors neck extension so that the head passes through the introitus and over the perineum with its smallest diameters. Comparing the Ritgen maneuver with simple perineal support in 1623 women, Jonsson and colleagues (2008) found a similar incidence of third-and fourth-degree tears, defined later (p. 528). FIGURE 27-1 Perineum is supported as the head crowns.


Obstentrics_Williams

Obstentrics_Williams. FIGURE 27-1 Perineum is supported as the head crowns. FIGURE 27-3 Modified Ritgen maneuver. Moderate upward pressure is applied to the fetal chin by the posterior hand covered by a sterile towel. The other hand applies occipital pressure. • Delivery of the Shoulders Following delivery of the fetal head, a inger is passed across the fetal neck to determine whether it is encircled by one or more umbilical cord loops. he nuchal cord incidence increases with gestational age and is found in nearly 25 percent of deliveries at term (Larson, 1997; Ogueh, 2006). If an umbilical cord coil is felt, it is slipped over the head if loose enough. If applied too tightly, the loop is cut between two clamps. Tight nuchal cords complicate approximately 6 percent of all deliveries but are not associated with worse neonatal outcome than those without a cord loop (Henry, 2013).


Obstentrics_Williams

Obstentrics_Williams. Following its delivery, the fetal head falls posteriorly, bringing the face almost into contact with the maternal anus. he occiput promptly turns toward one of the maternal thighs, and the head assumes a transverse position. This external rotation indicates that the bisacromial diameter, which is the distance between the shoulders, has rotated into the anteroposterior diameter of the pelvis. Most often, the shoulders appear at the vulva just after external rotation and are born spontaneously. If delayed, extraction aids controlled delivery. The sides of the head are grasped with two hands, and genle downward traction is applied until the anterior shoulder appears under the pubic arch (Fig. 27-4). Next, by an upward movement, the posterior shoulder is delivered. During delivery, abrupt or powerful force is avoided to avert fetal brachial plexus injury.


Obstentrics_Williams

Obstentrics_Williams. he rest of the body almost always follows the shoulders without diiculty. With prolonged delay, however, its birth may be hastened by moderate outward traction on the head and moderate pressre on the uterine fundus. Hooking the fingers in the axillae is avoided. This can injure upper extremity nerves and produce a transient or possibly permanent paralysis. Immediately after delivery of the newborn, a gush of amnionic luid that is often blood-tinged but not grossly bloody usually follows.


Obstentrics_Williams

Obstentrics_Williams. Previously, immediate nasopharyngeal bulb suctioning of the newborn was routine to remove secretions. It was found, however, that suctioning of the nasopharynx may lead to neonatal bradycardia (Gungor, 2006). he current American Heart Association neonatal resuscitation recommendations eschew most suctioning immediately following birth-even with meconium present (Chap. 33, p. 620). And with meconium-stained luid, routine intubation for tracheal suction is not recommended for vigorous or for nonvigorous neonates. Suctioning is reserved for neonates who have obvious obstruction to spontaneous breathing or who require positive-pressure ventilation (Wyckof, 2015). For suctioning, options are bulb syringe or suction catheter aspiration and may include intubation and suctioning if the airway is obstructed.


Obstentrics_Williams

Obstentrics_Williams. FIGURE 27-4 Delivery of the shoulders. A. Gentle downward traction to effect descent of the anterior shoulder. B. Delivery of the anterior shoulder completed. Gentle upward traction to deliver the posterior shoulder. The umbilical cord is cut between two clamps placed 6 to 8 cm from the fetal abdomen, and later an umbilical cord clamp is applied 2 to 3 cm from its insertion into the fetal abdomen. For term neonates, the timing of umbilical cord clamping remains debatable. Delayed umbilical cord clamping transfers a greater volume of blood to the newborn. A delay for up to 60 seconds may increase total body iron stores, expand blood volume, and decrease anemia incidence in the neonate (Andersson, 2011; Yao, 1974). his practice may be particularly valuable in populations in which iron deficiency is prevalent (Kc, 2017; World Health Organization, 2014).


Obstentrics_Williams

Obstentrics_Williams. Conversely, a higher hemoglobin concentration increases risks for hyperbilirubinemia and extended hospitalization for neonatal phototherapy (McDonald, 2013). Delayed cord clamping may also hinder timely and needed neonatal resuscitation. That said, early pilot studies are assessing the value of resuscitating newborns at the bedside to permit delayed clamping (Katheria, 2017; Winter 2017). Fortunately, in general, delayed umbilical cord clamping compared with early clamping does not worsen Apgar scores, umbilical cord pH, or respiratory distress caused by polycythemia. Regarding maternal outcomes, rates of postpartum hemorrhage are similar between early and delayed clamping groups (Andersson, 2013). Fewer data are available regarding cord "milking," in which the opera tor pushes blood through the cord toward the newborn. his clamping is clinically indicated (Upadhyay, 2013).


Obstentrics_Williams

Obstentrics_Williams. For the preterm neonate, delayed cord clamping has sev eral benefits. hese include higher red cell volume, decreased need for blood transfusion, and lower rates of intraventricu lar hemorrhage and of necrotizing enterocolitis (Backes, 2014; Rabe, 2012). For neonates who require expedited resuscitation, cord milking may have beneits to quickly transfer volume (Al-Wassia, 2015; Katheria, 2015; Patel, 2014). Still, because of rapid blood volume changes, the American Heart Associa tion currently suggests against the routine use of cord milking for neonates born <29 weeks' gestation (Wyckof, 2015). The American College of Obstetricians and Gynecologists (2017a) notes suicient evidence to support delayed umbili 30 to 60 seconds after birth. This opinion is also endorsed by the American Academy of Pediatrics (2017 a). The American Heart Association guidelines advise that the practice may have resuscitation at birth (Wyckof, 2015).


Obstentrics_Williams

Obstentrics_Williams. In the absence of a pelvic architecture abnormalit) or asynclitism, the occiput transverse (OT) position is usually transitoly. Thus, unless contractions are hypotonic, the head usually spontaneously rotates to an OA posItion. If rotation ceases because of poor expulsive forces, vaginal deliveY usually can be accomplished readily in several ways. he easiest is manual rotation of the occiput either anteriorly to OA or less commonly, posteriorly to occiput posterior. If either is successful, Le Ray and coworkers (2007) reported a 4-percent cesarean delivery rate compared with a 60-percent rate in women in whom manual rotation was not successful. Some recommend rotation with Kielland forceps for the persistent OT position as outlined in Chapter 29 (p. 561). These forceps are used to rotate the occiput to the anterior position, and delivery is accomplished with the same forceps or by substitution with Simpson, Tucker-McLane, or similar forceps.


Obstentrics_Williams

Obstentrics_Williams. In some cases, pelvic shape leads to a persistent OT position that is not easily overcome. For example, a platypelloid pelvis is lattened anteroposteriorly and an android pelvis is heart shaped. With these, space may be inadequate for occipital rotation to either an anterior or posterior position (Fig. 2-17, p. 31). Because of these concerns, undue force is avoided if forceps delivery is attempted. Approximately 2 to 10 percent of singleton term cephalic fetuses deliver in an occiput posterior (OP) position (Cheng, 2010). Many fetuses delivering OP are OA in early labor and relect malrotation during labor. Predisposing risks include epidural analgesia, nulliparity, greater fetal weight, and prior delivery with OP positioning (Cheng, 2006a; Gardberg, 2004; Lieberman, 2005). Regarding pelvic shape, an anthropoid pelvis and narrow subpubic angle can predispose (Barth, 2015; Ghi, 2016).


Obstentrics_Williams

Obstentrics_Williams. Women with a persistent OP position have higher associated rates of prolonged second-stage labor, cesarean delivery, and operative vaginal delivery. For women who deliver vaginally, rates of blood loss and of third-and fourth-degree lacerations are increased (Senecal, 2005).


Obstentrics_Williams

Obstentrics_Williams. plication rates then those born positioned OA. Cheng and coworkers (2006b) compared outcomes of 2591 women under going delivery with a persistent OP position with those of28,801 women whose newborns were delivered OA. Virtually every possible delivery complication was found more frequently with persistent OP position. Only 46 percent of these women deliv ered spontaneously, and the remainder accounted for 9 percent of cesarean deliveries performed. hese investigators also found that an OP position at delivery was associated with more adverse cord gases, birth trauma, Apgar scores <7, and intensive care nursery admission, among others. Similar results were reported by Ponkey (2003) and Fitzpatrick (2001) and their associates.


Obstentrics_Williams

Obstentrics_Williams. Methods to prevent persistent OP position and its associated morbidity have been investigated. First, digital examination for identiication of fetal head position can be inaccurate, and transabdominal sonography can be used to increase accuracy (Dupuis, 2005; Zahalka, 2005). The transducer is placed transversely just cephalad to the maternal mons pubis. In the sonogram, fetal orbits and nasal bridge lie ventrally, whereas the occiput apposes the lower sacrum. Such information may provide an explanation for prolonged second-stage labor or may identiy suitable candidates for rotation. Of other possible interventions, varying maternal position either antepartum or during labor does not appear to lower rates of persistent OP position (Desbriere, 2013; Kariminia, 2004; Le Ray, 2016).


Obstentrics_Williams

Obstentrics_Williams. The fetus in an OP position may be delivered either spontaneously or by operative vaginal delivery. First, if the bony pelvic outlet is roomy and the perineum is somewhat relaxed from prior deliveries, rapid spontaneous OP delivery will often take place. Conversely, if the perineum is resistant to stretch, secondstage labor may be appreciably prolonged. During each expulsive efort, the head is driven against the perineum to a much greater degree than when the head position is OA. This leads to greater rates of third-and fourth-degree lacerations (Groutz, 2011; Melamed, 2013).


Obstentrics_Williams

Obstentrics_Williams. In some cases, spontaneous vaginal delivery from an OP position does not appear feasible or expedited delivery is needed. Here, manual rotation with spontaneous delivery from an OA position may be preferred. This technique is described fully in Chapter 29 (p. 560). Successful rotation rates range from 47 to 90 percent. And, as would be expected, lower rates of cesarean delivery, vaginal laceration, and maternal blood loss follow rotation to OA position and vaginal delivery (Le Ray, 2005; Sen, 2013; Shafer, 2006, 2011). Disadvantageously, manual rotation is linked with higher cervical laceration rates. Thus, careful inspection of the cervix following rotation is mandatory.


Obstentrics_Williams

Obstentrics_Williams. For exigent delivery, forceps or vacuum device can be applied to a persistent OP position. This is often performed in conjunction with an episiotomy. Also, if the head is engaged, the cervix fully dilated, and the pelvis adequate, forceps rotation may be attempted for those with suitable skills. These operative vaginal techniques are detailed in Chapter 29 (p. 561). Infrequently, protrusion of fetal scalp through the introitus is the consequence of marked elongation of the fetal head from molding combined with formation of a large caput succedaneum. In some cases, the head may not even be engaged-that is, the biparietal diameter may not have passed through the pelvic inlet. In these, labor is characteristically long and descent of the head is slow. Careful palpation above the symphysis may disclose the fetal head to be above the pelvic inlet. Prompt cesarean delivery is appropriate.


Obstentrics_Williams

Obstentrics_Williams. At Parkland Hospital, spontaneous delivery or manual rotation is preferred for management of persistent OP position. When needed, either manual rotation to OA position followed by forceps delivery or forceps delivery from the OP position is used. If neither can be completed with ease and safety, cesarean delivery is performed. Following complete emergence of the fetal head during vaginal delivery, the remainder of the body may not rapidly follow. The anterior fetal shoulder can become wedged behind the symphysis pubis and fail to deliver using normally exerted downward traction and maternal pushing. Because the umbilical cord is compressed within the birth canal, this dystocia is an emergency. Several maneuvers, in addition to downward traction on the fetal head and neck, may be performed to free the shoulder. This requires a team approach, in which efective communication and leadership are critical.


Obstentrics_Williams

Obstentrics_Williams. Consensus regarding a speciic definition of shoulder dystocia is lacking. Some focus on whether maneuvers to free the shoulder are needed, whereas others use the head-to-body delivery time interval as deining (Beall, 1998). Spong and coworkers (1995) reported that the mean head-to-body delivery time in normal births was 24 seconds compared with 79 seconds in those with shoulder dystocia. These investigators proposed that a head-to-body delivery time >60 seconds be used to define shoulder dystocia. Currently, however, the diagnosis continues to rely on the clinical perception that the normal downward traction needed for fetal shoulder delivery is inefective.


Obstentrics_Williams

Obstentrics_Williams. Because of these difering deinitions, the incidence of shoulder dystocia varies. One recent review cites a clinically useful average of 1 percent of all deliveries (Ouzounian, 2016). The incidence has increased in recent decades, likely due to increasing fetal birthweight (MacKenzie, 2007; 0verland, 2014). Increased identiication and documentation may also raise the incidence (Kim, 2016).


Obstentrics_Williams

Obstentrics_Williams. In general, shoulder dystocia poses greater risk to the fetus than to the mother. The main maternal risks are serious perineal tears and postpartum hemorrhage, usually from uterine atony but also from lacerations (Gauthaman, 2016; Rahman, 2009). In contrast, significant neonatal neuromusculoskeletal injury and asphyxia are concerns. These specific injuries are described in Chapter 33 (p. 630). In one review of 1177 shoulder dystocia cases, brachial plexus injury was diagnosed in 11 percent and clavicular or humeral fracture in 2 percent (Chauhan, 2014). MacKenzie and associates (2007) reviewed 514 cases. Of the neonates, 7 percent showed evidence of acidosis at delivery, and 1.5 percent required cardiac resuscitation or developed hypoxic ischemic encephalopathy (HIE). In another review of 200 cases, rates of severe fetal acidosis and HIE were each 0.5 percent if delivery was completed within 5 minutes. These rates rose to 6 and 24 percent, respectively, with delivery delays �5 minutes


Obstentrics_Williams

Obstentrics_Williams. 200 cases, rates of severe fetal acidosis and HIE were each 0.5 percent if delivery was completed within 5 minutes. These rates rose to 6 and 24 percent, respectively, with delivery delays �5 minutes (Leung, 2011a).


Obstentrics_Williams

Obstentrics_Williams. Fetal macrosomia, maternal obesity, prolonged second-stage labor, and a prior event raise risks for shoulder dystocia (Mehta, 2004; Overland, 2009; Schummers, 2015). Although these factors are clearly associated with this complication, identification of individual instances before the fact has proved to be impossible. The American College of Obstetricians and Gynecologists (2017 c) reviewed studies and concluded that: 1. Most cases of shoulder dystocia cannot be accurately predicted or prevented. 2. Elective induction of labor or elective cesarean delivery for all women suspected of having a macrosomic fetus is not appropriate. 3. Planned cesarean delivery may be considered for the nondiabetic woman with a fetus whose estimated fetal weight is > 5000 g or for the diabetic woman whose fetus is estimated to weigh >4500 g.


Obstentrics_Williams

Obstentrics_Williams. There is a corresponding rise in the incidence of shoulder dystocia with increasing birthweight (Acker, 1985; 0verland, 2012; Stotland, 2004). Commonly cited maternal characteristics associated with increased fetal birthweight are obesity, postterm pregnancy, multiparity, and diabetes (Jolly, 2003; Koyanagi, 2013). The combination of fetal macrosomia and maternal diabetes mellitus escalates the frequency of shoulder dystocia (Langer, 1991; Nesbitt, 1998). This predisposition may stem from the fact that fetuses of diabetic women have larger shoulder and extremity circumferences and greater shoulder-to-head and chest-to-head size diferences relative to comparable-weight fetuses of nondiabetic mothers (McFarland, 1998; Modanlou, 1982). That said, translating these specific measurements into stand-alone sonographic clinical thresholds has shown poor predictive sensitivity (Burkhardt, 2014).


Obstentrics_Williams

Obstentrics_Williams. Preventively, early labor induction has yielded conflicting results. In one study, approximately 800 women with suspected macrosomic fetuses were randomized either to early induction between 37 and 39 weeks or to expectant care (Boulvain, 2015). Dystocia rates were lowered by two thirds in the intervention group, and neither group sufered brachial plexus injury. Although not measured, this practice is balanced against morbidity of early delivery. Moreover, the poor accuracy of antepartum fetal weight prediction should be considered as well (Hoopmann, 2010; Mlin, 2016; Noumi, 2005). In contrast, an earlier randomized study of 284 women showed that rates of shoulder dystocia were not lowered by early induction at 38 weeks (Gonen, 1997).


Obstentrics_Williams

Obstentrics_Williams. As previously discussed, cesarean delivery may be considered to prevent shoulder dystocia. hat said, Rouse and Owen (1999) concluded that a prophylactic cesarean delivery policy for macrosomic fetuses would require more than 1000 cesarean deliveries with attendant morbidity to avert a single permanent brachial plexus injury. he risk of recurrent shoulder dystocia ranges from 1 to 13 percent (Bingham, 2010; Moore, 2008; Ouzounian, 2013). For many women with prior shoulder dystocia, a trial of labor may be reasonable. he American College of Obstetricians and Gynecologists (2017 c) recommends that estimated fetal weight, gestational age, maternal glucose intolerance, and severity of prior neonatal injury be evaluated and risks and benefits of cesarean delivery discussed with any woman with a history of


Obstentrics_Williams

Obstentrics_Williams. FIGURE 27-5 The McRoberts maneuver. The maneuver consists of removing the legs from the stirrups and sharply flexing the thighs up toward the abdomen. The assistant is also providing suprapubic pressure simultaneously (arrow). shoulder dystocia. After discussion, either mode of delivery may be appropriate.


Obstentrics_Williams

Obstentrics_Williams. shoulder dystocia. After discussion, either mode of delivery may be appropriate. Because shoulder dystocia cannot be accurately predicted, clinicians should be well versed in its management principles. Because of ongoing cord compression with this dystocia, one goal is to reduce the head-to-body delivery time. This is balanced against the second goal, which is avoiding fetal and maternal injury from aggressive manipulations. Accordingly, an initial gentle attempt at traction, assisted by maternal expulsive eforts, is recommended. Adequate analgesia is certainly ideal. Some clinicians advocate performing a large episiotomy to provide room for manipulations. Episiotomy itself does not lower brachial plexus injury rates but raises third-and fourthdegree laceration rates (Gurewitsch, 2004; Paris, 2011; SagiDain, 2015). Episiotomy may be elected to complete needed maneuvers.


Obstentrics_Williams

Obstentrics_Williams. After gentle traction, various techniques can be used to free the anterior shoulder from its impacted position behind the symphysis pubis. A more detailed discussion of these and the topic is found in Cunningham and Gilstrap s Operative Obstetrics, 3rd edition (Cunningham, 2017). Of these, moderate suprapubic pressure can be applied by an assistant, while downward trac tion is applied to the fetal head. Pressure is applied with the heel of the hand to the anterior shoulder wedged above and behind the symphysis. The anterior shoulder is thus either depressed or rotated, or both, so the shoulders occupy the oblique plane of the pelvis. Here, the anterior shoulder can be freed.


Obstentrics_Williams

Obstentrics_Williams. The McRoberts maneuver is often selected next if additional steps are needed. The maneuver consists of removing the legs from the stirrups and sharply lexing them up toward the abdomen. Suprapubic pressure is often concurrently applied (Fig. 27-5). Gherman and associates (2000) analyzed the McRoberts maneuver using x-ray pelvimetry. hey found that the procedure caused straightening of the sacrum relative to the lumbar vertebrae, rotation of the symphysis pubis toward the maternal head, and a decrease in the angle of pelvic inclination. Although this does not increase pelvic dimensions, pelvic rotation cephalad tends to free the impacted anterior shoulder. Gonik and coworkers (1989) tested the McRoberts position objectively with laboratory models and found that the maneuver reduced the forces needed to free the fetal shoul der. If unsuccessful, most move next either to free the posterior shoulder or to rotate the bisacromial diameter into one of the oblique diameters of the maternal


Obstentrics_Williams

Obstentrics_Williams. needed to free the fetal shoul der. If unsuccessful, most move next either to free the posterior shoulder or to rotate the bisacromial diameter into one of the oblique diameters of the maternal pelvis.


Obstentrics_Williams

Obstentrics_Williams. With delivey of the posterior shoulder, the accoucheur carefully sweeps the posterior arm of the fetus across its chest, followed by deliveY of the arm (Fig. 27-6). If possible, the operator's ingers are aligned parallel to the long axis of the fetal humerus to lower bone fracture risks. The shoulder girdle is then rotated into one of the oblique diameters of the pelvis with subsequent delivery of the anterior shoulder.


Obstentrics_Williams

Obstentrics_Williams. Of rotational maneuvers, Woods (1943) reported that by progressively rotating the posterior shoulder 180 degrees in a corkscrew fashion, the impacted anterior shoulder could be released. his is frequently referred to as the Woods corkscrew maneuver (Fig. 27-7). Rubin (1964) recommended two maneuvers. First, the fetal shoulders are rocked from side to side by applying force to the maternal abdomen. If this is not successful, the pelvic hand reaches the most easily accessible fetal shoulder, which is then pushed toward the anterior surface of the chest. This maneuver most oten abducts both shoulders, which in turn produces a smaller bisacromial diameter. This permits displacement of the anterior shoulder from behind the symphysis (Fig. 27-8).


Obstentrics_Williams

Obstentrics_Williams. If the above are initially unsuccessful, they may be repeated, and finally other methods may be elected. With an allours maneuver, also called the Gaskin maneuver, the parturient rolls onto her knees and hands. Here, downward traction against the head and neck attempts to free the posterior shoulder (Bruner, 1998). Challenges with this include immobility from regional analgesia and time lost in patient repositioning. In some, the posterior arm is inaccessible for delivery. Cluver and Hofmeyr (2009) describedposterior axila sling traction to deliver the posterior arm. With this alternative method, a suction catheter is threaded under the axilla and both ends are brought together above the shoulder. Upward and outward traction on the catheter loop delivers the shoulder. In a small series of 19 cases, this maneuver was successful in 18 cases. However, neonatal injury included three cases of humeral fracture and one permanent and four transient cases ofErb palsy (Cluver, 2015).


Obstentrics_Williams

Obstentrics_Williams. FIGURE 27-6 Delivery of the posterior shoulder for relief of shoulder dystocia. A. The operator's hand is introduced into the vagina along the fetal posterior humerus. B.The arm is splinted and swept across the chest, keeping the arm flexed at the elbow. C. The fetal hand is grasped and the arm extended along the side of the face. The posterior arm is delivered from the vagina. ....�. i" Jr-.. � FIGURE 27-7 Woods maneuver. The hand is placed behind the posterior shoulder of the fetus. The shoulder is then rotated in a corkscrew manner so that the impacted anterior shoulder is released. FIGURE 27-8 The second Rubin maneuver. A. The bisacromial diameter is aligned vertically. B. The more easily accessible fetal shoulder (the anterior is shown here) is pushed toward the anterior chest wall of the fetus (arrow). Most often, this results in abduction of both shoulders, which reduces the bisacromial diameter and frees the impacted anterior shoulder.


Obstentrics_Williams

Obstentrics_Williams. Deliberate fracture of the anterior clavicle using the thumb to press it toward and against the pubic ramus can be attempted to free the shoulder impaction. In practice, however, deliberate fracture of a large neonate's clavicle is diicult. If successful, the fracture will heal rapidly and is usually trivial compared with brachial nerve injury, asphyxia, or death.


Obstentrics_Williams

Obstentrics_Williams. he Zavanelli maneuver involves replacement of the fetal head into the pelvis followed by cesarean delivery (Sandberg, 1985). Terbutaline, 0.25 mg, is given subcutaneously to produce uterine relaxation. he irst part of the maneuver consists of returning the head to an OA or OP position. The operator flexes the head and slowly pushes it back into the vagina. Cesarean delivery is then performed. Sandberg (1999) reviewed 103 reported cases. It was successful in 91 percent of cephalic cases and in all cases of breech head entrapments. Despite successful replacement, fetal injuries were common bur may have resulted from the multiple manipulations used before the Zavanelli maneuver (Sandberg, 2007).


Obstentrics_Williams

Obstentrics_Williams. Symphysiotomy, in which the intervening symphyseal cartilage and much of its ligamentous support is cut to widen the symphysis pubis, is described in Chapter 28 (p. 548). It has been used successfully for shoulder dystocia (Goodwin, 1997; Hartield, 1986). Maternal morbidity can be signiicant due to urinary tract injury. Cleidotomy consists of cutting the clavicle with scissors or other sharp instruments and is usually done for a dead fetus (Schramm, 1983). Hernandez and Wendel (1990) suggest use of a shoulder dystocia drill to better organize emergency management: 1. Call for help-mobilize assistants and anesthesia and pediatric personnel. Initially, a gentle attempt at traction is made. Drain the bladder if it is distended. 2. A generous episiotomy may be desired at this time to aford room posteriorly. 3.


Obstentrics_Williams

Obstentrics_Williams. 2. A generous episiotomy may be desired at this time to aford room posteriorly. 3. Suprapubic pressure is used initially by most practitioners because it has the advantage of simplicity. Only one assistant is needed to provide suprapubic pressure, while normal downward traction is applied to the fetal head. 4. The McRoberts maneuver requires two assistants. Each assistant grasps a leg and sharply lexes the maternal thigh toward the abdomen. These maneuvers will resolve most cases of shoulder dystocia. If the above listed steps fail, the following steps may be attempted, and any of the maneuvers may be repeated: 5. Delivery of the posterior arm is attempted. With a fully extended arm, however, this is usually diicult to accomplish. 6. Woods screw maneuver is applied. 7. Rubin maneuver is attempted.


Obstentrics_Williams

Obstentrics_Williams. Delivery of the posterior arm is attempted. With a fully extended arm, however, this is usually diicult to accomplish. 6. Woods screw maneuver is applied. 7. Rubin maneuver is attempted. The American College of Obstetricians and Gynecologists (2017c) has concluded that no one maneuver is superior to another in releasing an impacted shoulder or reducing the chance of injury. Performance of the McRoberts maneuver, however, is deemed a reasonable initial approach. In one review of more than 2000 cases, Hofman and colleagues (2011) noted an 84-percent success rate with posterior shoulder delivery and comparable rates of neonatal injury compared with other standard methods. This contrasts with a review of 205 cases, in which posterior shoulder delivery yielded greater neonatal injury rates than rotational methods (Leung, 201i1b). Spain and associates (2015) found that duration rather than a speciic maneuver increased neonatal injury.


Obstentrics_Williams

Obstentrics_Williams. Importantly, progression from one maneuver to the next should be organized and methodical. As noted, the urgency to relieve the dystocia should be balanced against potentially lnJurious traction forces and manipulations. Lerner and coworkers (201l) in their evaluation of 127 shoulder dystocia cases reported that all neonates without sequelae from shoulder dystocia were born by 4 minutes. Conversely, most depressed neonates-57 percent-had head-to-body delivery intervals >4 minutes. The percentage of depressed neonates rose sharply after 3 minutes.


Obstentrics_Williams

Obstentrics_Williams. Shoulder dystocia training and protocols using simulationbased education and drills has evidence-based support. These tools improve performance and retention of drill steps (Buerkle, 2012; Crofts, 2008; Grobman, 201l). Their use has translated into improved neonatal outcome in some, but not all, investigations (Crofts, 2016; Fransen, 2017; Kim, 2016; Walsh, 201l). The American College of Obstetricians and Gynecologists (2012) also has created a Patient Safety Checklist to guide the documentation process with shoulder dystocia.


Obstentrics_Williams

Obstentrics_Williams. In 2014, 0.7 percent of deliveries in the United States were planned home births and 0.2 percent were unplanned (MacDorman, 2016). Of unplanned births in a 15-year epoch in Norway, 69 of 6027 or 1.1 percent resulted in fetal or neonatal death. This high rate was attributable to infection, prematurity, and placental abruption (Gunnarsson, 2017). Multiparity and distance from the hospital were ascribed risks (Gunnarsson, 2014). In the United States, youth, lack of prenatal care, minority race, and lower educational attainment were associated risks for unplanned home birth (Declercq, 2010).


Obstentrics_Williams

Obstentrics_Williams. In contrast, the demographics of women choosing planned home birth in the United States favor those who are white, nonsmoking, self-pay, college-educated, and multiparous (MacDorman, 2016). As perceived beneits, planned delivery at home for those with low-risk pregnancies results in fewer medical interventions that include labor augmentation, episiotomy, operative vaginal delivery, and cesarean delivery (Bolten, 2016; Cheyney, 2014). Regarding the safety of planned home birth, data from randomized trial are lacking, and large observational studies derive from heterogeneous care systems, whose results may not be generalizable. For example, several developed countries deliver at home a large volume of carefully screened women, delivered by midwives with substantial training and in a setting closely integrated with the local health-care system (Birthplace in England Collaborative Group, 2011; de Jonge, 2015; Hutton, 2016). The level of such coordination in the United States is less


Obstentrics_Williams

Obstentrics_Williams. closely integrated with the local health-care system (Birthplace in England Collaborative Group, 2011; de Jonge, 2015; Hutton, 2016). The level of such coordination in the United States is less uniform.


Obstentrics_Williams

Obstentrics_Williams. Overall, risks of home births in the United States are small but greater than those of hospital delivery. Midwife-attended home births carry a neonatal mortality risk of 1.3 per 1000 births. This is a nearly fourfold greater rate compared with midwife-attended hospital births. The most common underlying causes of death are those attributed to labor and delivery events, to congenital anomalies, and to infection. Of neonatal injuries, rates of neonatal seizure and serious neurological dysfunction are similarly elevated in home-birth groups (Grunebaum, 2013, 2014, 2017; Snowden, 2015; Wasden, 2016). Importantly, substantial risks attend home birth for those with prior cesarean delivery, with breech presentation, and with multifetal gestation (Cheyney, 2014; Cox, 2015). The American College of Obstetricians and Gynecologists (2017b) considers these to be absolute contraindications. Further, the College considers accredited hospitals and birthing centers to be the safest site for birth but


Obstentrics_Williams

Obstentrics_Williams. Obstetricians and Gynecologists (2017b) considers these to be absolute contraindications. Further, the College considers accredited hospitals and birthing centers to be the safest site for birth but recognizes the autonomy of the well-counseled patient.


Obstentrics_Williams

Obstentrics_Williams. As one option for pain relief, some women choose to spend part of first-stage labor in a large water tub. With this practice, one Cochrane review found lower rates of anesthesia block use and no greater adverse neonatal or maternal efects compared with traditional labor (Cluett, 2009).


Obstentrics_Williams

Obstentrics_Williams. For delivery, however, water birth carries greater concern for neonatal harm and without proven benefits. Case reports describe aspiration leading to fresh-water drowning (Pinette, 2004). The risk of cord avulsion during water birth approximates 3 per 1000 births, and stems primary from abruptly bringing the newborn out of the water (Schafer, 2014). Last, case reports also enumerate serious infections, which emphasize the need for rigorous sanitizing protocols. hat said, in most large studies comparing land and water births, overall maternal or neonatal infection rates are not increased (Bovbjerg, 2016; Burns, 2012; Thoeni, 2005). In sum, several reviews comment on study shortcomings and isolated complications but do not identiy definitive evidence for overall greater rates of neonatal harm from water birth in low-risk populations (Davies, 2015; Taylor, 2016). However, given the paucity of robust data and potential for serious complications, the American College of Obstetricians and


Obstentrics_Williams

Obstentrics_Williams. from water birth in low-risk populations (Davies, 2015; Taylor, 2016). However, given the paucity of robust data and potential for serious complications, the American College of Obstetricians and Gynecologists (2016a) currently recommend that "birth occur on land, not in water."


Obstentrics_Williams

Obstentrics_Williams. This practice refers to medically unnecessary vulvar and perineal modification. In the United States, it is a federal crime to perform unnecessary genital surgery on a girl younger than 18 years. That said, forms of female genital mutilation are practiced in countries throughout Africa, the Middle East, and Asia. As many as 200 million women worldwide have undergone one of these procedures, and approximately 513,000 girls in the United States were at risk for this practice in 2012 (Goldberg, 2016; UNICEF, 2016). Cultural sensitivity is imperative, because many women may be ofended by the suggestion that they have been assaulted or mutilated (merican College of Obstetricians and Gynecologists, 2014).


Obstentrics_Williams

Obstentrics_Williams. The World Health Organization (2008) classifies genital mutilations into four types (Table 27-1). Long-term complications from surgery and its associated scarring include infertility, genital pain, diminished sexual quality of life, and propensity for urogenital infection (Almroth, 2005; Andersson, 2012; Nour, 2015). In general, women with significant symptoms following type III procedures are candidates for corrective surgery. Specifically, division of midline scar tissue to reopen the vulva is termed deinibulation. Female genital mutilation has been associated with some adverse maternal and neonatal complications. The World TABLE 27-1. World Health Organization Classification of Female Genital Mutilation Type I Partial or total removal of the clitoris and/or prepuce Type II Partial or total removal of the clitoris and the labia minora, with or without labia majora excision


Obstentrics_Williams

Obstentrics_Williams. Type I Partial or total removal of the clitoris and/or prepuce Type II Partial or total removal of the clitoris and the labia minora, with or without labia majora excision Type III Partial or total labial minora and/or majora excision, followed by fusion of the wound, termed infibulation, to cover and narrow the vagina. With or without clitoridectomy Type IV Pricking, piercing, incising, scraping, cautery, or other injury to female genitalia Adapted from the World Health Organization, 2008. Health Organization (2006, 2008) estimated that these proce dures increased perinatal morbidity rates by 10 to 20 per 1000. Small increased risks for prolonged labor, cesarean delivery, and postpartum hemorrhage are also found (Berg, 2014; Chibber, 2011; Wuest, 2009). Importantly, the psychiatric consequences can be profound.


Obstentrics_Williams

Obstentrics_Williams. To prevent obstetrical complications, deinibulation can be performed either antepartum or intrapartum (Fig. 27-9) (Esu, 2017). In women not undergoing deinibulation, anal sphincter tear rates with vaginal delivery may be increased (Berggren, 2013; Rodriguez, 2016). In our experiences, intrapartum deinibulation in many cases allows successful vaginal delivery without major complications.


Obstentrics_Williams

Obstentrics_Williams. hese surgeries are performed with increasing frequency in reproductive-aged women, and thus pregnancy following these procedures is not uncommon. Logically, there are concerns for symptom recurrence following vaginal delivery, and high-quality data to aid evidenced-based decisions are limited. For women with prior stress urinary incontinence surgery, slightly greater protection against postpartum incontinence is gained by elective cesarean delivery (Pollard, 2012; Pradhan, 2013). Stated another way, most women with prior corrective surgery for incontinence can be delivered vaginally without symptom recurrence. Also, cesarean delivery is not always protective. Obviously, symptom recurrence and the need for additional vaginal surgery should be weighed against the surgical risk of cesarean delivery (Groenen, 2008). In those with prior surgeries for anal incontinence or pelvic organ prolapse, only scant information regarding outcomes is available. Such cases require individualization.


Obstentrics_Williams

Obstentrics_Williams. Rarely, delivery can be obstructed by extreme hydrocephaly, by body stalk anomaly, or by massive fetal abdominal enlargement from a greatly distended bladder, ascites, or organomegaly (Costa, 2012; Sikka, 2011). With milder forms of hydrocephaly, if the biparietal diameter is < 10 cm or if the head circumference is <36 cm, then vaginal delivery may be permitted (Anteby, 2003).


Obstentrics_Williams

Obstentrics_Williams. FIGURE 27-9 Deinfibulation. Although not shown here, lidocaine is first infiltrated along the planned incision if regional analgesia is not in place already. As protection, two fingers of one hand are insinuated behind the shelf created by fused labia but in front of the urethra and crowning head. The shelf is then incised in the midline. After delivery, the raw edges are sutured with rapidly absorbable material to secure hemostasis. (Reproduced with permission from Hawkins JS: Lower genital tract procedures. In Yeomans ER, Hoffman BL, Gilstrap LC III, et al (eds): Cunningham and Gilstrap's Operative Obstetrics, 3rd ed. New York, McGraw-Hili Education, 201o7.)


Obstentrics_Williams

Obstentrics_Williams. In rare cases in which neonatal death has occurred or is certain due to associated anomalies, vaginal delivery may be reasonable, but the head or abdomen must be reduced in size for delivery. Removal of luid by cephalocentesis or paracentesis with sonographic guidance can be performed intrapartum. As described on page 523, cleidotomy can shorten the bisacromial diameter. For hydrocephalic fetuses that are breech, cephalocentesis can be accomplished suprapubically when the aftercoming head enters the pelvis. Currently, these practices are more germane in developing countries. • Delivery of the Placenta hird-stage labor begins immediately after fetal birth and ends with placental delivery. Goals include delivery of an intact placenta and avoidance of uterine inversion or postpartum hemorrhage. The latter two are grave intrapartum complications and constitute emergencies, as described in Chapter 41 (p. 755).


Obstentrics_Williams

Obstentrics_Williams. Immediately after newborn birth, uterine fundal size and consistency are examined. If the uterus remains irm and there is no unusual bleeding, watchful waiting until the placenta separates is the usual practice. Neither massage nor downward fundal pressure is employed, but the fundus is frequently palpated to ensure that it does not become atonic and illed with blood from placental separation. To prevent uterine inversion, umbilical cord traction must not be used to pul the placenta rom the uterus. Signs of separation include a sudden gush of blood into the vagina, a globular and firmer fundus, a lengthening of the umbilical cord as the placenta descends into the vagina, and elevation of the uterus into the abdomen. With the last, the placenta, having separated, passes down into the lower uterine segment and vagina. Here, its bulk pushes the uterine body upward.


Obstentrics_Williams

Obstentrics_Williams. These signs appear within minutes after newborn delivery, and the median time ranges from 4 to 12 minutes (Combs, 1991; Frolova, 2016; Shinar, 2016b). Once the placenta has detached from the uterine wall, the mother may be asked to bear down, and the intraabdominal pressure often expels the placenta into the vagina. These eforts may fail or may not be possible because of analgesia. After ensuring that the uterus is contracted irmly, the umbilical cord is kept slightly taut but is not pulled. Pressure is exerted by a hand wrapped around the fundus to propel the detached placenta into the vagina (Fig. 27-10). Concurrently, the heel of the hand exerts downward pressure between the symphysis pubis and the uterine fundus. This also aids inversion prevention. Once the placenta passes through the introitus, pressure on the uterus is relieved. The placenta is then gently lifted away. Care is taken to prevent placental membranes from being torn of and left behind. If the membranes begin to


Obstentrics_Williams

Obstentrics_Williams. the introitus, pressure on the uterus is relieved. The placenta is then gently lifted away. Care is taken to prevent placental membranes from being torn of and left behind. If the membranes begin to tear, they are grasped with a clamp and removed by gentle teasing (Fig. 27-11).


Obstentrics_Williams

Obstentrics_Williams. FIGURE 27-10 Expression of placenta. Note that the hand is not trying to push the fundus of the uterus through the birth canal! As the placenta leaves the uterus and enters the vagina, the uterus is elevated by the hand on the abdomen while the cord is held in position. The mother can aid in the delivery of the placenta by bearing down. As the placenta reaches the perineum, the cord is lifted, which in turn lifts the placenta out of the vagina. FIGURE 27-11 Membranes that were somewhat adhered to the uterine lining are separated by gentle traction with ring forceps. • Management of the Third Stage


Obstentrics_Williams

Obstentrics_Williams. FIGURE 27-11 Membranes that were somewhat adhered to the uterine lining are separated by gentle traction with ring forceps. • Management of the Third Stage Practices within the third stage of labor may be broadly considered as either expectant or active management. Expectant management involves waiting for placental separation signs and allowing the placenta to deliver either spontaneously or aided by nipple stimulation or gravity (World Health Organization, 2012). In contrast, active management of third-stage labor consists of early cord clamping, controlled cord traction during placental delivery, and immediate administration of prophylactic oxytocin. The goal of this triad is to limit postpartum hemorrhage (Begley, 2015; Jangsten, 2011; Westhof, 2013).


Obstentrics_Williams

Obstentrics_Williams. As noted earlier, delayed cord clamping does not increase postpartum hemorrhage rates, and thus early clamping is a less important component of this trio. Similarly, cord traction may also be less critical (Deneux-haraux, 2013; Du, 2014; Giilmezoglu, 2012). Uterine massage following placental delivery is recommended by many, but not all, to prevent postpartum hemorrhage. We support this with the caveat that evidence for this practice is not strong (Abdel-Aleem, 2010).


Obstentrics_Williams

Obstentrics_Williams. Therefore, utero tonics play an essential role to decrease postpartum blood loss. Choices include oxytocin (Pitocin), misoprostol (Cytotec), carboprost (Hemabate), and the ergots, namely ergonovine (Ergotrate) and methylergonovine (Methergine). In addition, a combination agent of oxytocin and ergonovine (Syntometrine) is used outside the United States. Also in other countries, carbetocin (Duratocin), a long-acting oxytocin analogue, is available and efective for hemorrhage prevention during cesarean delivery (Attilakos, 2010; Su, 2012). Of these, the World Health Organization (2012) recommends oxytocin as a first-line agent. Ergot-based drugs and misoprostol are alternatives in settings that lack oxytocin.


Obstentrics_Williams

Obstentrics_Williams. Utero tonics may be given before or after placental expulsion without afecting rates of postpartum hemorrhage, placental retention, or third-stage labor length (Soltani, 2010). If they are given before delivery of the placenta, however, they may entrap an undiagnosed, undelivered second (Win. hus, abdominal palpation should conirm no additional fetuses. Notably, this concern is less relevant with current widespread sonography use.


Obstentrics_Williams

Obstentrics_Williams. Synthetic oxytocin is identical to that produced by the posterior pituitary. Its action is noted at approximately 1 minute, and it has a mean half-life of 3 to 5 minutes. When given as a bolus, oxytocin can cause profound hypotension. Secher and coworkers (1978) reported that an intravenous bolus of 10 units of oxytocin caused a marked transient fall in blood pressure with an abrupt increase in cardiac output. Svansrrom and associates (2008) conirmed those findings. hese hemodynamic changes could be dangerous for women hypovolemic from hemorrhage or those with certain types of cardiac disease. Thus, oxytocin should be given as a dilute solution by continuous intravenous infusion or as an intramuscular injection.


Obstentrics_Williams

Obstentrics_Williams. Water intoxication can result from the antidiuretic action of high-dose oxytocin if administered in a large volume of electro lyte-free dextrose solution (Whalley, 1963). Thus, if oxytocin is to be administered in high doses for a considerable period of time, its concentration should be increased rather than increas ing the infusion flow rate.


Obstentrics_Williams

Obstentrics_Williams. Despite the routine use of oxytocin, no standard prophylactic dose has been established for its use following either vaginal or cesarean delivery. Our practice is to add 20 units (2 mL) of oxytocin per liter of infusate. his solution is administered after delivery of the placenta at a rate of 10 to 20 mUmin-200 to 400 mU/min-for a few minutes until the uterus remains irmly contracted and bleeding is controlled. he infusion rate then is reduced to 1 to 2 mUmin until the mother is ready for transfer from the recovery suite to the postpartum unit. The infusion is usually then discontinued. For women without intravenous access, 10 units of intramuscular oxytocin are injected.


Obstentrics_Williams

Obstentrics_Williams. Ergonovine and methylergonovine have similar activity levels in myometrium, and only methylergonovine is currently manufactured in the United States. These ergot alkaloid agents do not provide superior protection against postpartum hemorrhage compared with oxytocin. \10reover, safety and tolerability are greater with oxytocin (Liabsuetrakul, 2011). For these reasons, ergot alkaloid agents are considered second-line for prevention of postpartum hemorrhage. If selected, a 0.2-mg dose of methylergonovine is slowly given intravenously in a period not less than 60 seconds to avoid sudden hypertension (Novartis, 2012). Methylergonovine is relatively contraindicated in the hypertensive woman.


Obstentrics_Williams

Obstentrics_Williams. Misoprostol is a prostaglandin E, analogue, which has proved inferior to oxytocin for postpartum hemorrhage prevention (Tun:alp, 2012). However, in resource-poor settings that lack oxytocin, misoprostol is suitable for hemorrhage prophylaxis and is given as a single oral 600-�g dose (Mobeen, 2011; World Health Organization, 2012). Notably, although oxytocin is preferred for prevention of hemorrhage, ergot alkaloids and prostaglandins playia greater role in postpartum hemorrhage treatment, discussed in Chapter 41 (p. 759). • Manual Removal of Placenta