Use of magnesium sulphate during pregnancy to treat certain conditions in mothers or lower the risk of a baby being born with cerebral palsy is not associated with a higher probability of harm in newborns, a study suggests.
The study, “Antenatal magnesium sulphate and adverse neonatal outcomes: A systematic review and meta-analysis,” was published in PLOS Medicine.
Magnesium sulphate, sometimes called Epsom salts, is often administered for maternal neuroprotection during pregnancy in cases of preeclampsia — high blood pressure and signs of damage to other organs — or eclampsia — onset of seizures or coma in pregnant women with preeclampsia.
Magnesium sulphate is also given to pregnant women at a high risk of pre-term birth, because it can lower the risk of cerebral palsy in their newborns. Evidence for these benefits is well-established, but it’s not entirely clear what potential harm there might be in using magnesium sulfate.
“Until now there has been speculation this beneficial treatment could unintentionally harm the unborn child, but it’s been unclear either way,” Emily Shepherd, a PhD candidate at the University of Adelaide and co-author of the study, said in a press release.
To address this question, Shepherd and her colleagues analyzed the currently available scientific literature on the subject.
“Our team undertook a systematic review that analyzed almost 200 studies, including 40 randomized trials,” Shepherd said. The trials alone included data for 19,265 pregnancies.
The studies ranged in depth, breadth, and methodology; as such, the researchers performed analyses by grouping studies together — for example, one analysis used data from trials comparing magnesium sulphate with a placebo, while another analysis used data from trials that tested different dosages of magnesium sulphate. The non-trial studies were analyzed in a separate review.
Researchers then looked at the compiled data holistically to determine whether there was an increased risk of adverse events during the perinatal period (around the time of birth) associated with magnesium sulphate use.
“Overall,” the researchers wrote in their paper, “no clear difference in our primary review outcome, perinatal death, was shown in the randomised trials comparing antenatal [during pregnancy] magnesium sulphate with placebo/no treatment, nor in regimen comparisons in randomised trials. … Results for secondary adverse neonatal outcomes were reassuring, with very few clear differences observed between antenatal magnesium sulphate and placebo/no treatment or between different magnesium sulphate regimens.”
The researchers did note that there may be some particular instances wherein this may not hold true — for example, some of the data they found suggested that newborns born very early or with very low body weight may be adversely affected by magnesium sulphate use — but at present, there simply isn’t enough data on such relatively rare cases to say for sure one way or the other.
As such, more research on such cases is warranted, they say: “Our evaluation thus provides a firm basis for any further, narrowly focused studies of specific outcomes and characteristics.”
“Our findings support the continued use of magnesium sulphate as a safe treatment,” Shepherd concluded.