Delivery of the premature infant.

Significantly preterm delivery should ideally occur in centers with neonatal intensive care units and be attended by pediatric staff. The progress of labor, fetal heart rate patterns, and indications of fetal compromise differ substantially from those seen at term. Steroids and antibiotics are frequently indicated; research is focused on the use of phenobarbital, magnesium sulfate, and thyrotropin-releasing hormone. Selective use of episiotomy may be beneficial. The suggestion that cesarean delivery before the onset of labor reduces intraventricular hemorrhage in very low birth weight infants has not been demonstrated clearly. Vertical uterine incision is frequently needed for cesarean delivery of very low birth weight infants. Cesarean delivery is usually employed for very low birth weight infants in breech presentation or if either fetus in a twin gestation is not in vertex presentation, but is usually not needed for face or compound vertex presentations. Ultrasound examination should be performed to identify major malformations associated with preterm delivery. Serious morbidity is uncommon after 32 weeks' gestation; mortality and disability are concentrated in those with birth weights less than 1,000 grams. In the latter group, the decision of whether to intervene for fetal indications should be considered as soon as it appears delivery is likely. This decision should be based on early pregnancy dating, when available. In the absence of reliable dates, ultrasound measurements of biparietal diameter and femur length are more reliable than estimated fetal weight.