Neonatal medical admission in a term and late-preterm cohort exposed to magnesium sulfate

Objective: The purpose of this study was to estimate neonatal intensive care unit and special care unit (NICU) admission rates and care needs among term and late-preterm neonates who are exposed to antenatal magnesium sulfate. Study Design: We conducted a retrospective cohort study of all singleton neonates of <35 weeks' gestation who were exposed immediately antenatally to magnesium sulfate for maternal eclampsia prophylaxis (August 2006 through July 2008). Results: Fifty-one of 242 neonates (21.1%) who, at <35 weeks' gestation, had been exposed to antenatal magnesium sulfate were admitted to the NICU. NICU admission was associated in a dose-dependent fashion with total hours and mean dose of magnesium: >12 hours exposure, odds ratio, 2.81 (95% confidence interval, 1.316.03); >30 g exposure, odds ratio, 2.59 (95% confidence interval, 1.225.51). Infants in NICU who were diagnosed with hypermagnesemia required fluid or nutritional support more frequently (91.3% vs 39.3%; P < .001) than those without hypermagnesemia. Conclusion: Antenatal magnesium sulfate exposure is associated with NICU admission among term and late-preterm neonates in a dose-dependent fashion. Fluid and nutritional assistance commonly are needed in this cohort.