Neonatal magnesium levels are safe after maternal MgSO4 administration: a comparison between unexposed preterm neonates and neonates exposed for fetal neuroprotection or maternal eclampsia prevention-a cohort study

To objective of this study was to compare neonatal magnesemia in the first 15 days of neonatal life between three groups: a control group not exposed to MgSO4, a neuroprotection group, and an eclampsia prevention group, and to explore its associations with child outcomes. A retrospective single-centre cohort study was performed in a tertiary care setting. Infants admitted at the neonatal intensive care unit born between 24 and 32 weeks' gestation, regardless of etiology of preterm birth, were included. The mean outcome measure was neonatal magnesemia (mmol/L). Linear mixed regression of neonatal magnesemia on exposure group and day of life was done. Generalised estimating equation models of child outcomes on neonatal magnesemia according to exposure group and day of life were made. The analyses showed that in neonatal magnesemia is significantly higher in the preeclampsia group compared to the control and neuroprotection groups. On the day of birth, this is irrespective of maternal magnesemia (preeclampsia vs control groups), and the maternal total dose or duration of MgSO4 administration (preeclampsia vs neuroprotection group). No differences were found in short-term composite outcome between the three groups. Conclusion: We found mean differences in neonatal magnesemia between children not exposed to MgSO4 antenatally, children exposed for fetal neuroprotection, and children exposed for maternal eclampsia prevention. A 4-g loading and 1-g/h maintenance doses, for fetal neuroprotection and eclampsia prevention, appear to be safe on the short term for the neonate.

Automated summary

This study aims to compare neonatal magnesemia in the first 15 days of neonatal life between three groups and explore its associations with child outcomes. The results show that neonatal magnesemia is significantly higher in the preeclampsia group compared to the control and neuroprotection groups. The study found mean differences in neonatal magnesemia between children not exposed to MgSO4 antenatally, children exposed for fetal neuroprotection, and children exposed for maternal eclampsia prevention.