In a recent study, researchers assessed the neuroprotective effects of taking magnesium sulphate during pregnancy on premature babies.
Babies born prematurely are at a higher risk of dying in early life, and those who survive have a higher risk of neurological impairment and disability. Cerebral palsy and cognitive dysfunction are the most common neurological impairments observed in premature babies, born at or less than 37 weeks gestation. With the rise of premature births seen in many countries, finding an effective therapy for reducing the risk of neurological impairments in premature babies has become a priority.
Magnesium sulphate first demonstrated its effects on reducing cerebral palsy from observational studies in the mid-1990s, and many randomized trials have further explored this since. In an article published in PLOS Medicine, researchers in New Zealand and Australia published their findings from an individual-participant data meta-analysis of past clinical trials evaluating the benefit of magnesium sulphate in reducing the risk of neurological impairment in premature babies.
In their study, the researchers assessed whether certain participant or treatment characteristics affected the treatment effects of magnesium sulphate given to pregnant women at risk of preterm birth. Eligible trials for inclusion in the analysis were those in which women at risk of preterm birth were randomized to magnesium sulphate treatment or no treatment. Further, trials were also included if their main goal was preventing fetal abnormalities or if they reported on early childhood neurological outcomes. Five randomized controlled studies were identified and included in the meta-analysis. The risk of bias was assessed and determined to be low within and across the included studies.
Strong Protective Effects on Rates of Cerebral Palsy
The results of the analysis found no significance in preventing premature baby death rates when exposed to magnesium sulphate versus no treatment. However, magnesium sulphate did show a strong protective effect on the rates of cerebral palsy, for both moderate and severe cerebral palsy, that was similar across all studied trials. The results also showed that there were no reports of treatment-related severe adverse events to the pregnant women taking magnesium sulphate. In addition, subgroup analysis showed that the treatment effects did not differ based on characteristics such as gestational age, time from first treatment, total dose received, use of maintenance therapy, or single versus multiple births.
The study is strengthened by its individual-participant data meta-analysis approach as it is considered a gold standard in systematic review. Another strength of this analysis was the ability to include individual participant data from clinical trials that reported on child neurodevelopmental outcomes with magnesium sulphate. At the time of this study’s analysis, there were two ongoing trials whose data will update these current findings once completed. Limitations to the study include a lack of data from some trials for certain pre-specified analyses and the low maternal and fetal event rates for some clinical events, therefore limiting the ability to detect certain overall or subgroup differences.
Magnesium Sulphate Lowers the Risk of Cerebral Palsy
As a whole, the researchers conclude that magnesium sulphate given to women at risk of preterm birth lowers the risk of cerebral palsy development in their premature baby. They further highlight that no specific subgroup of women or babies would benefit more or less from magnesium sulphate treatment, such as the reason for premature birth or treatment use at varying preterm gestational ages. Under appropriate supervision, magnesium sulphate is a relatively inexpensive and easy to administer treatment that may be effective in improving preterm birth outcomes and ultimately lead to meaningful health benefits on a global scale.
Written by Maggie Leung, PharmD
Reference: Crowther, C. A., Middleton, P. F., Voysey, M., Askie, L., Duley, L., Pryde, P. G., . . . Doyle, L. W. (2017). Assessing the neuroprotective benefits for babies of antenatal magnesium sulphate: An individual participant data meta-analysis. PLOS Medicine, 14(10). doi:10.1371/journal.pmed.1002398
