What Health Concerns Affect a Moderately Preterm Baby?

Most Moderately Preterm Babies Face No Long-Term Consequences

Newborn baby sleeping in incubator
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What does it mean if your doctor says your baby will be a moderately preterm baby? What can you expect?

What Is a Moderately Preterm Baby?

According to many definitions, a moderately preterm baby is one born between about 31 and 34 weeks gestational age. A micro preemie is born before 26 weeks gestational age; a very premature baby is born between 27 and 30 weeks gestational age, and a late preterm baby is born between 34 and 36 weeks gestational age.

Because the fetus grows so quickly during the last months of pregnancy, a moderately preterm baby is very different from one born earlier or later. Moderately preterm babies face a unique set of challenges and have different health problems from other premature babies.

What Does a Moderately Preterm Baby Look Like?

Although they are smaller than full-term babies, moderately preterm babies look much like babies born later. They no longer have the thin skin and lack of body fat that very premature babies have. They usually weigh between about 3 1/2 to 5 pounds.

If you are visiting a newborn moderately preterm baby, NICU equipment will probably be more intimidating than the baby himself. Expect to see:

  • Incubators: Although moderately preterm babies have begun to fill out, most don't have enough body fat to keep themselves warm. The baby may be in an incubator or, for the first several hours of life, under a radiant warmer.
  • Respiratory support: About half of moderately preterm babies need respiratory support at birth. Nasal CPAP and nasal cannulas are most commonly used, although some moderately preterm babies need mechanical ventilation.
  • IV lines: Because moderately preterm babies have immature digestive systems, milk feedings are slowly introduced and increased over a period of several days. Peripheral IVs are often used to give the baby nutrition while feeds are increased, although PICC lines and umbilical catheters may also be used.
  • Monitoring equipment: Stickers on a moderately preterm baby's chest and feet or wrists will monitor the baby's heart rate, breathing rate, and oxygen saturation.
  • Feeding tubes: Because moderately preterm babies are not strong enough to take in enough nourishment to gain weight, a tube will go from the baby's mouth (OG tube) or nose (NG tube) to the stomach. The tube will be used to give any milk feedings that the baby cannot take by breast or bottle.

What Health Concerns Will a Moderately Preterm Baby Face?

A moderately preterm baby is usually mature enough at birth to escape the most serious health problems of prematurity. Most of the health concerns faced by moderately preterm babies are short-lived and resolved before NICU discharge.

  • Jaundice: Jaundice is caused by the normal breakdown of red blood cells after birth. During this breakdown, the body creates waste products that premature babies can't get rid of very well. Preemies may need to be treated for several days with phototherapy to help.
  • Apnea of prematurity: Apnea (when breathing stops) and bradycardia (when the heart rate slows down) are common in premature babies. Moderately preterm babies may suffer from apnea of prematurity for several weeks while their bodies mature. Apnea of prematurity is treated with medication and close monitoring.
  • Poor feeding: Moderately preterm babies are not strong enough to take all of their feedings from the breast or bottle, and may not coordinate sucking, swallowing, and breathing well. It can be frustrating for parents to leave their babies in the NICU when they seem to be well in every way, just because they are not strong enough to breastfeed or bottle feed.
  • Respiratory distress: Lung development isn't complete until a baby has reached full term, and moderately preterm babies sometimes have trouble breathing at birth. They may breathe too quickly (tachypnea), have low oxygen saturation, or show other signs that they are having trouble breathing. Respiratory support may be needed, especially during the first few days of life.

    What Is Tachypnea?

    Tachypnea is rapid breathing. Newborn babies usually breathe between 40 and 60 breaths per minute. A respiratory rate faster than 60 breaths per minute is called tachypnea. Both premature babies and babies born at term may breathe rapidly due to a condition called transient tachypnea of the newborn (TTN), a mild condition. Babies with TTN may require respiratory support, and usually breathe normally within 1 or 2 days. In premature babies, tachypnea may be a sign of respiratory distress syndrome, a more serious condition that may take longer to recover from.

    How Long Will a Moderately Preterm Baby Stay in the NICU?

    All preterm babies must meet certain milestones before they can be safely discharged from the NICU. They must be able to eat, breathe, and stay warm on their own. Moderately preterm babies take several weeks to meet these milestones and are usually discharged at approximately 36 weeks gestational age.

    What Long-Term Problems Will a Moderately Preterm Baby Face?

    Most moderately preterm babies leave the NICU with no lasting effects of prematurity. Some may need short-term care after discharge; they may bring an apnea monitor home with them or need oxygen at home for a few months. About 15% will have mild disabilities such as developmental delays or trouble in school, and another 5% to 8% will have more serious physical and cognitive limitations.

    There are many things that parents can do to help make sure that their babies have the best possible outcome:

    • Get early prenatal care: Moms can reduce their risk for preterm birth by getting early prenatal care. Expectant moms should talk with their doctors early on about their chances for having a premature baby; according to the March of Dimes, these conversations are too infrequent.
    • Spend time in the NICU: If you have given birth to a moderately preterm baby, spend as much time in the NICU as you can. Learn about your baby's condition, bond with your baby, and get good at feeding your preemie.
    • Explore early intervention: If your baby shows any signs of developmental delay or has any severe health problems in the NICU, talk to your pediatrician about early intervention (EI). Early intervention programs are free to parents and can help preterm babies catch up to their peers more quickly.


    Gunter, J. The Preemie Primer Da Capo, 2010.

    Kirkby, S, Greenspan, J, Kornhauser, M, and Schneiderman, R. "Clinical Outcomes and Cost of the Moderately Preterm Infant." Advances in Neonatal Care April 2007; 7, 80-87.

    Qiu, X et al. "Comparison of Singleton and Multiple-Birth Outcomes of Infants Born at or Before 32 Weeks of Gestation." Obstetrics & Gynecology Feb 2008; 111, 365-371.

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