Tocolysis does not improve neonatal outcome in patients with preterm rupture of membranes

To investigate the effects of magnesium sulfate therapy in premature preterm rupture of membranes (PPROM), this retrospective cohort study of deliveries after PPROM over a 3-year period was performed. Gestational age-matched patients, who received magnesium sulfate therapy after PPROM, were compared with those who did not receive tocolysis. Deliveries within 48 hours (47 versus 22%) and a week (92 versus 44%) of PPROM occurred more frequently in those who received tocolysis. Cervical dilation and frequency of contractions were not different between the two groups. There was no difference at 24 hours in the delivery rates (36 versus 22%). Population demographics and neonatal/obstetrical outcomes were similar between the two groups except for a shorter latency in patients who received tocolysis (60 [1-245] versus 127 [1-1848] hours, median [range]). Magnesium sulfate therapy does not appear to improve maternal or neonatal outcome in PPROM and may in fact shorten the latency period.