Tocolysis in advanced preterm labor: impact on neonatal outcome

Chart review of 73 patients with 3.5 cm or more dilation, intact membranes, and regular contractions at less than 36 weeks. Forty-four (group A) received tocolysis with magnesium sulfate, and 13 of the 44 also received indomethacin. Twenty-nine (group B) received no tocolysis. Obstetric and neonatal outcomes were compared. Demographic factors and admission gestational age, cervical dilation, effacement, and uterine activity were similar. Twenty-one of the 44 in group A versus 3 of 29 in group B had delivery delayed by more than 48 hours (p = 0.002). Group A had a lower incidence of severe respiratory distress syndrome; 4 of 48 babies in group A versus 9 of 32 in group B (p = 0.04; RR = 0.47; confidence interval [CI], 0.2, 1.0). Tocolysis in advanced preterm labor delays delivery by more than 48 hours in 50% of patients. The neonatal benefits of aggressive tocolysis in cases with advanced cervical dilation may outweigh the potential maternal risks of tocolysis, particularly in the setting of extreme prematurity. Delay in delivery enabling steroid enhancement of pulmonary maturity reduces the severity of respiratory distress syndrome.