Neurobehavioral effects of neonatal hypermagnesemia.

To investigate the effects on the newborn infant of maternal magnesium therapy for treatment of pre-eclampsia, we studied 36 hypermagnesemic infants born to pre-eclamptic mothers treated with MgSO4, 18 neonates born to untreated pre-eclamptic mothers, and 25 infants born to normal mothers. Impairment of neuromuscular transmission, as well as neurobehavioral differences when compared to controls, were found in hypermagnesemic infants. Awareness of the changes produced in the neonate by magnesium is important for accurate clinical assessment of the infant's condition, as well as for anticipating the postnatal interaction of magnesium with other drugs administered during labor and delivery.