The effect of maternal magnesium sulfate treatment on neonatal morbidity in <= 1000-gram infants

We evaluated the effect of maternal magnesium sulfate treatment on selected neonatal outcomes in less than or equal to 1000-g infants. In a 1-year (19 92-1993) observational study, the National Institute of Child Health and Hu man Development Network of Maternal-Fetal Medicine Units collected outcome data for 799 infants whose birth weights were less than or equal to 1000 g. Only singleton infants, with a gestational age > 20 weeks who were not the product of an induced abortion were included. Our analysis was further lim ited to those infants without major congenital anomalies, who were deemed p otentially viable by the obstetrician, whose mother would have undergone a cesarean delivery for fetal indications, and who survived greater than 2 da ys. Outcomes were compared in infants whose mothers did and did not receive magnesium sulfate for labor tocolysis. Among the 124 women who did and the 184 who did not receive magnesium sulfate tocolytic therapy, the frequenci es of grade III or IV intraventricular hemorrhage (16 vs. 20%, p = 0.34), s eizure activity (7 vs. 10%, p = 0.35), grade III or IV retinopathy of prema turity (21 vs. 18% p = 0.59), abnormal neurological exam (28 vs. 28%, p = 0 .91), intact survival to 120 days or to discharge (48 vs. 44%, p = 0.54), a nd infant mortality (23 vs. 31%, p = 0.10) were similar. Multiple logistic regression analysis was used to control for the effect of potential confoun ders (specifically, gestational age) and confirmed the lack of a significan t association between maternal magnesium sulfate treatment for tocolysis an d selected neonatal outcomes in this population of less than or equal to 10 00-gram infants.