Magnesium sulphate for preventing preterm birth in threatened preterm labour

Magnesium sulphate is used to inhibit uterine activity in women in preterm labour to prevent preterm birth. To assess the effectiveness and safety of magnesium sulphate therapy given to women in threatened preterm labour with the aim of preventing preterm birth and its sequelae. We searched the Cochrane Pregnancy and Childbirth Group trials register (May 2002) and the Cochrane Controlled Trials Register (The Cochrane Library, Issue 2, 2002). Women thought to be in preterm labour. Types of interventions: Magnesium sulphate as the only tocolytic, administered intravenously or orally, compared with either placebo, no treatment or alternative tocolytic therapy. Types of outcome measures: Measures of effectiveness, complications, women's satisfaction with their care and health service use. Assessments of trial eligibility, quality and data extractions were done by at least two of the reviewers. Over 2000 women were recruited into the 23 included trials. Only nine trials were rated of high quality for the concealment of allocation. In the magnesium sulphate versus control (all studies) no difference was seen for the risk of birth within 48 hours of treatment for women given magnesium sulphate compared with controls when using a random effects model (relative risk (RR) 0.85, 95% confidence interval (CI) 0.58-1.25, 11 trials, 881 women). No benefit was seen for magnesium sulphate on the risk of giving birth preterm (