1 g/h magnesium sulfate maintenance for eclampsia prevention is enough

We conducted two systematic reviews including only randomized controlled trials (RCTs) comparing magnesium sulfate vs placebo/no treatment, as well as 2 g/h vs 1 g/h magnesium sulfate maintenance regimens for prevention of eclampsia. Medline, Cochrane Library, EMBASE, PubMed Central, Scopus, ClinicalTrial.gov were electronically searched from their inception to February 2025. In the five RCTs comparing magnesium sulfate vs placebo/no treatment, a 2-g maintenance dose was used in two RCTs including 176 pregnancies, while a 1 g maintenance dose was used in three RCTs including 5447 pregnancies. Eclampsia incidence was 0.57% with the 2 g/h regimen and 0.76% with the 1 g/h regimen (OR 1.33, 95% CI: 0.18-9.60), while maternal side effects were significantly higher in the 2 g/h regimen (67% vs 22%, OR 7.05, 95% CI: 4.22-11.78). In the five RCTs (n = 283) comparing 2 g/h vs 1 g/h maintenance regimens, no case of eclampsia was reported with either regimen, and maternal side effects were significantly higher in the 2 g/h group (71% vs 42%, OR 1.69, 95% CI: 1.06-2.71). In conclusion, magnesium sulfate maintenance regimen of 1 g/h seems as effective as the 2 g/h regimen for the prevention of eclampsia, with decreased incidence of maternal side effects.