Can the Umbilical Cord Knot?

Get answers to all your umbilical cord questions.

The umbilical cord is a critical lifeline that looks like a white, twisted telephone cord. Its two arteries and single vein transport nutrients and oxygen from your body through the placenta to your baby. The umbilical cord grows as your baby does, so by the time you deliver the cord will probably measure about 2 feet long. That's just the right length to allow you to hold your baby in your arms and begin nursing her even before you deliver the placenta.

Before birth. Many parents worry unnecessarily about knots in the umbilical cord. The truth is that most babies can do all sorts of somersaults and wave their umbilical cords around like jump ropes without doing any harm to themselves or the cords. A true cord knot can occur when a baby passes through a loop of umbilical cord. This usually happens early in pregnancy, though, when your baby is still small enough to move about freely. Most of the time the knot stays loose and does nothing to impede the baby's development.

Cord prolapse. Another potential--but extremely rare--problem is a cord that slips out of the uterus into the vagina either before or during labor. This can lead to the baby's oxygen supply being cut off if the cord is compressed. You may feel the cord protruding yourself if the cord descends into your vagina. This most often happens when a baby is breech or premature, especially if your water breaks, because the baby's head is not in position to prevent the cord from being carried into your cervix by the rush of amniotic fluid.

If you should feel the cord protruding, support it with a clean towel while you lie on your side and phone your emergency room and provider immediately. You will probably be sent to the hospital where you will be prepared for a cesarean delivery.

Cord abnormalities. Abnormalities in cord length can be associated with risk factors to your child's health. For instance, a short cord may prevent the baby from going deeper into the pelvis during labor. A cord that's overly long poses a higher risk of knots and tangles around the baby's neck either before or during delivery. If at birth only one artery and one vein are visible in the cord (instead of the usual two arteries and one vein), there's a chance that your baby may suffer health problems related to his cardiovascular or gastrointestinal system; that's why your doctor will examine the cord carefully after delivery. Remember that these abnormalities are extremely rare.

Monitoring baby. Most cord problems cause no harm to your baby. The best way to know if there's a problem with your baby's umbilical cord is by charting your baby's activity. If you don't notice at least 8-10 movements in 1 hour, then count for a second hour; you may have been counting while the baby was asleep. If you still don't detect any movement or the baby's movements have decreased, call your doctor. She will likely ask you to go to the office or hospital for either an ultrasound or nonstress test. They may tell you that all is well, but it's important to know for sure while there is still time for a cesarean delivery should it be necessary.

Originally published in You & Your Baby: Pregnancy.
