Before 39 Weeks, Let Labor Begin On Its Own
Some women may request delivery before 39 weeks of gestation when neither the mother nor the infant is at risk if the pregnancy is allowed to progress. However, research indicates that infants born prior to 39 weeks are at higher risk for more short- and long-term morbidities than those born after 39 weeks. These morbidities are potentially preventable if labor is allowed to begin on its own.
Clinical evidence also shows that a fetus experiences a significant amount of development and growth in several key organ systems between 37 and 39 weeks of gestation.
Delivery prior to 39 weeks is appropriate only if medically indicated and with documented fetal lung maturity, as specified by American College of Obstetricians and Gynecologists (ACOG) guidelines.1
In November 2013, ACOG and the Society for Maternal-Fetal Medicine released a committee opinion replacing "term" delivery with new designations based on gestational age. Babies born at weeks 39 and 40 are now considered "full term." Learn more about the new definition of full-term pregnancy based on NICHD research.
Health Risks to Mother and Infant
Nonmedically indicated deliveries prior to 39 weeks are associated with increased risks to the health of both mother and infant.
- Greater risk of being admitted into the NICU2
- 20% greater risk of complications after birth, including:
- 5% greater risk of developmental disabilities6
- 63% greater chance of death within the first year of life7
Risks to the mother:
- Postpartum depression8
- Stronger and more frequent contractions9
- Needing a cesarean delivery, which carries its own risks, including:10
Watch this roundtable discussion to learn more about the factors contributing to the rising rates of early term and late preterm births, the potential consequences of births before 39 weeks of gestation, and evidence-based guidelines for delivery prior to 39 weeks. The roundtable discussion is moderated by Dr. Catherine Spong, Acting Director, NICHD.
Recent research findings indicate that delaying delivery until 39 weeks of pregnancy or later—if there is no medical reason to deliver earlier—is not associated with increased rates of stillbirths in the United States. This research, funded by the NICHD and other groups, contradicts findings from an earlier study that waiting until 39 weeks to deliver could lead to more stillbirths.