Magnesium sulphate still prevents cerebral palsy — and the benefit fades by school age

The edition in brief

The updated Cochrane review of antenatal magnesium sulphate for fetal neuroprotection includes six randomised trials with 5,917 women and 6,759 fetuses, all conducted in high-income countries. Up to two years' corrected age, magnesium sulphate reduced cerebral palsy (risk ratio 0.71, 95% CI 0.57-0.89; number needed to treat 60) and death or cerebral palsy (0.87, 0.77-0.98), both high-certainty evidence, with no detectable effect on death alone. By early school age no difference was detectable in any outcome, on low-certainty evidence. Maternal adverse effects severe enough to stop treatment were about three times commoner (average risk ratio 3.21, 1.88-5.48). In a French prospective cohort of 642 children with confirmed congenital cytomegalovirus infection, long-term sequelae occurred exclusively after first-trimester maternal primary infection; autism spectrum disorder was diagnosed in 11 children, all symptomatic at birth, and every case had temporal lobe white matter abnormality on imaging. Among 1,258 pregnancies with chronic hypertension, an estimated fetal weight below the tenth percentile at 35-36 weeks predicted superimposed preeclampsia only when accompanied by abnormal Dopplers. In 121,017 postmenopausal UK Biobank participants, premature menopause carried a 32% higher risk of a first chronic disease than menopause after 50. An expert review updates guidance on disease-modifying therapy around pregnancy in multiple sclerosis.