Ultrasonically estimated weight and gestational age. Predictors of neonatal respiratory distress syndrome.

Information from 504 women who had undergone real-time ultrasound examination within 72 hours of childbirth was used to evaluate the relationship between the product of ultrasonically estimated fetal weight (in kilograms) times ultrasonically estimated gestational age (in weeks) and neonatal morbidity and mortality. If this product was greater than 40, there were no neonatal deaths (excluding severe congenital abnormalities); if the product was greater than 80, there were no cases of significant respiratory distress syndrome. These data may prove to be highly useful in the rapid evaluation of preterm labor or other obstetric complications.