Preterm infants are at increased risk for a number of health problems, including death, cerebral palsy, developmental delays, infection, and vision and hearing problems. Some studies have suggested that infants delivered vaginally before 32 weeks’ gestation are less likely to survive through infancy than are those delivered by a planned cesarean. Additional studies suggest that the vaginally delivered infants are also more likely to suffer injury and health effects after passing through the birth canal. Cesarean delivery, especially in the early preterm period, poses risks for the mother, such as hemorrhage, bladder injury, and other complications. Women who undergo cesarean delivery are also at risk for rupture of the uterus during labor and other complications in subsequent pregnancies.
To assess the risks of vaginal delivery for preterm infants, researchers supported by the Pregnancy and Perinatology Branch compared nearly 3,000 women who attempted to deliver vaginally to those who had delivered by a planned cesarean before 32 weeks because of a health risk to the mother or baby.
For the fetus in the head first position, the success rate for attempted vaginal delivery was high; 84% of women delivered vaginally. Infants in the head-first position were as likely to survive after an attempted vaginal delivery as those delivered by planned cesarean delivery.
However, when the fetus was positioned feet-first (breech presentation), survival rates for deliveries before 32 weeks were considerably higher among infants delivered by planned cesarean delivery (PMID: 22840720) than for those delivered vaginally.