Short- and long-term outcomes in babies born after antenatal magnesium treatment

To identify the prenatal events associated with adverse outcome in babies born at less than 32 weeks' gestation, including antenatal magnesium sulfate treatment.

A case-control study was performed to examine the effect of long-term tocolysis with MgSO4. Long-term neonatal and infantile adverse outcomes were defined as one of the following: intraventricular hemorrhage, periventricular leukomalacia, cerebral palsy and infantile death.

Data were analyzed for 425 cases (236 who received magnesium sulfate and 189 control cases who did not). Perinatal deaths included 13 cases that had received magnesium (5.5%) and 17 control cases (9.0%). Long-term neonatal and infantile adverse outcomes were noted in 80 cases. The factor associated with an increased risk of combined adverse outcome after adjustment for confounding effects was the administration of corticosteroids (adjusted odds ratio [OR] 0.47, 95% confidence interval [CI] 0.27-0.81), but not magnesium sulfate (OR 0.82, 95% CI 0.48-1.40). In the subgroup that also received ritodrine (n = 315), magnesium sulfate was given to 195 cases. In this group, the factor associated with an increased risk of combined adverse outcome (n = 64) after adjustment for the confounding effects was also corticosteroids (adjusted OR 0.25, 95% CI 0.13-0.49), but magnesium sulfate was not associated with an increase in risk (OR 0.64, 95% CI 0.34-1.22).

Long-term tocolysis with magnesium sulfate is not a significant factor related to the occurrence of neonatal and infantile adverse outcomes. Further study is needed to clarify the dose-response effect of magnesium sulfate.