A randomised controlled trial of intravenous magnesium sulphate versus placebo in the management of women with severe pre-eclampsia

Abstract

Objective: To determine whether the administration of prophylactic intravenous magnesium sulphate reduces the occurrence of eclampsia in women with severe pre-eclampsia.

Design: Randomised controlled trial.

Setting: A tertiary referral obstetric unit.

Population: Eight hundred and twenty-two women with severe pre-eclampsia requiring termination of pregnancy by induction of labour or caesarean section.

Methods: The women were randomised to receive either placebo (saline) or magnesium sulphate intravenously. The investigators were blinded to the contents of the pre-mixed solutions.

Main outcome measure: The occurrence of eclampsia in the two groups.

Results: The data of 699 women were evaluated. Fourteen were withdrawn after randomisation. The overall incidence of eclampsia was 1.8%. Of 345 women who received magnesium sulphate, one developed eclampsia (0.3%); in the placebo group, 11/340 women (3.2%) developed eclampsia (relative risk 0.09; 95% confidence interval 0.01-0.69; P = 0.003).

Conclusion: The use of intravenous magnesium sulphate in the management of women with severe pre-eclampsia significantly reduced the development of eclampsia.