Magnesium sulfate for fetal neuroprotection in preterm labor: an updated systematic review and meta-analysis of randomized controlled trials

Objective: Antenatal magnesium sulfate has been reported to reduce the risk of neurological impairment in fetuses born to women at risk of preterm labor. However, the evidence to support its use is conflicting. We conducted this meta-analysis to assess the efficacy and safety of magnesium sulfate in women at risk of preterm labor as new research is available from RCTs giving insights into MgSO4 treatment among differing gestational age groups.

Study design: We searched various electronic databases, including MEDLINE (via PubMed), Embase, the Cochrane Library, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform portal from 1990 till 31st March 2024 to retrieve all randomized controlled trials (RCTs) that investigated the use of magnesium sulfate in women at risk of preterm labor with or without intent of fetal neuroprotection We used the revised Cochrane Risk of Bias tool (RoB 2.0) to assess the quality of the included randomized controlled trials. RevMan 5.4 was used to conduct all statistical analyses using a random-effects model. Our Meta-analysis was registered with the PROSPERO International Register of Systematic Reviews (CRD42024532421).

Results: Our meta-analysis including eight RCTs showed that magnesium sulfate reduced the risk of cerebral palsy without a significant change in pediatric mortality. The change was evident in moderate to severe cerebral palsy. Magnesium sulfate showed no beneficial effect in most of the secondary outcomes.

Conclusions: This meta-analysis found antenatal magnesium sulfate reduces the risk of cerebral palsy with no difference in pediatric mortality between the magnesium or no magnesium treatment groups, which is a positive finding. However, there is still substantial heterogeneity between the studies, so there is a need for further exploration and discussion. The implications of this review include a concern for developing nations where resources and availability of magnesium sulfate are limited. Hence, further studies are needed to determine the exact dosage, timing, and whether maintenance dosage of magnesium sulfate is required or not and for how long.