Effect of magnesium sulfate administration for neuroprotection on latency in women with preterm premature rupture of membranes

Objective This study aims to evaluate whether magnesium sulfate administration for neuroprotection prolongs latency in women with preterm premature rupture of membranes (PPROM) between 24 and 31^6/7 weeks' gestation. Study Design This is a secondary analysis of a randomized controlled trial of magnesium sulfate for prevention of cerebral palsy. Gravid women with a singleton pregnancy between 24 and 31^6/7 weeks' gestation with PPROM without evidence of labor were randomized to receive magnesium sulfate, administered intravenously as a 6-g bolus followed by a constant infusion of 2 g per hour up to 12 hours, or placebo. Maternal outcomes for this analysis were delivery in less than 48 hours and in less than 7 days from randomization. Neonatal outcomes included a composite of respiratory distress syndrome, interventricular hemorrhage grades 3 or 4, periventricular leukomalacia, sepsis, necrotizing enterocolitis, retinopathy of prematurity, or death. Results A total of 1,259 women were included. The rate of delivery < 48 hours was not different in the magnesium sulfate and the placebo groups (22.2 and 20.7%, p= 0.51). Delivery< 7 days was similar between groups (55.4 and 51.4%, p = 0.16). Median latency was also similar between groups (median [interquartile range], 6.0 days [range, 2.4-13.8 days] and 6.6 days [range, 2.4-15.1 days], p= 0.29). Composite neonatal outcomes did not differ between groups.