Magnesium sulphate and other anticonvulsants for women with pre-eclampsia

BACKGROUND: Pre-eclampsia is a relatively common complication of pregnancy. Anticonvulsants are used in the belief they help prevent eclamptic fits and subsequent poor outcomes for mother and infant. OBJECTIVES: The objective of this review was to assess the effects of anticonvulsants for women with pre-eclampsia on the women and their children. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group trials register, and the Cochrane Controlled Trials Register, 1999 Issue 3. SELECTION CRITERIA: Randomised trials comparing anticonvulsants with placebo or no anticonvulsants or comparisons of different anticonvulsants in women with pre-eclampsia. DATA COLLECTION AND ANALYSIS: Trial quality was assessed and data were extracted independently by two reviewers. MAIN RESULTS: Nine studies were included. Comparing magnesium sulphate with placebo/no anticonvulsant the relative risk (RR) of eclampsia was 0.33, 95% confidence interval (CI) 0.11 to 1.02. There was no significant difference detected in the risk of caesarean section (RR 1.04, 95% CI 0.92 to 1.17). Magnesium sulphate appeared to be better than phenytoin at reducing the risk of eclampsia (RR 0.05, 95% CI 0.00 to 0.84). However there was an increased risk of caesarean section with magnesium sulphate compared to phenytoin (RR 1.21, 95% CI 1.05 to 1. 41). No statistically significant differences were reported for any other clinically important outcomes. Studies comparing magnesium sulphate and diazepam were too small for any reliable conclusions. REVIEWER'S CONCLUSIONS: There is not enough evidence to establish the benefits and hazards of anticonvulsants for women with pre-eclampsia. If an anticonvulsant is used, magnesium sulphate appears to be the best choice.