Notes: Objective To evaluate the effectiveness of magnesium sulphate in the treatment of eclampsia and pre-eclampsia by a systematic quantitative overview of controlled clinical trials.Design Online searching of the MEDLINE database between 1966 and 1995, and scanning of the bibliography of known primary studies and review articles on the use of magnesium sulphate in eclampsia and pre-eclampsia. Study selection, study quality assessment and data extraction were performed independently by two reviewers under masked conditions. Where possible outcome data from trials were pooled and summarised using the Mantel-Haenszel method.Participants One thousand seven hundred and forty-three women with eclampsia and 2390 with pre-eclampsia included in nine randomised trials that evaluated the effects of magnesium sulphate.Main outcome measures Seizure activity and maternal death.Results In eclampsia, recurrence of seizures was less common with magnesium sulphate therapy compared with phenytoin (odds ratio [OR] 0.27, 95% CI 0.17.0.45, P= 0.00) and diazepam (OR 0–41, 95% CI 0.30–0.57, P= 0.00). As indicated by the point estimate, there was a trend towards a reduction in maternal mortality with magnesium sulphate in eclampsia (OR 0.51,95% CI 0.24–1.07, P= 0.10versus phenytoin; OR 0.78, 95% CI 0.41–1.45, P= 0.52versus diazepam). When used for seizure prophylaxis in pre-eclampsia, magnesium sulphate was found to be more effective than phenytoin (OR 0.15, 95% CI 0.03–0.72, P= 0.01).Conclusion Magnesium sulphate is a superior drug in preventing the recurrence of seizures in eclampsia and in seizure prophylaxis in pre-eclampsia.

Notes: Objective To evaluate the clinical usefulness of Doppler analysis of the uterine artery velocity waveform in the prediction of pre-eclampsia and its associated complications of intrauterine growth retardation and perinatal death.Design Quantitative systematic review of observational diagnostic studies using online searching of the MEDLINE database coupled with scanning of the bibliographies of primary and review articles including known unpublished studies.Material Twenty-seven studies involving 12,994 subjects stratified into population subgroups at low and high risk of developing pre-eclampsia and its complications.Outcome measures The outcome measures studied were: 1. the development of pre-eclampsia; 2. intrauterine growth retardation; and 3. perinatal death. The main meta-analyses were the flow velocity waveform ratio ± diastolic notch derived by transabdominal Doppler ultrasound as the measurement parameter. The analyses were conducted using likelihood ratio as a measure of diagnostic accuracy. A likelihood ratio of 1 indicates that the test has no predictive value for the outcome. Prediction for the outcome event is considered conclusive with likelihood ratios of 〉 10 or 〈 0.1 for a positive and negative test result, respectively. Moderate prediction can be achieved with likelihood ratios of 5–10 and 0.1–0.2 whereas likelihood ratios values of 1–5 and 0.2–1 would generate only minimal prediction.Results In the low risk population a positive test result, predicted pre-eclampsia with a pooled likelihood ratio of 6.4 (95% CI 5.7–7.1), while a negative test result had a pooled likelihood ratio of 0.7 (95% CI 0.6–0.8). For intrauterine growth retardation the pooled likelihood ratio was 3.6 (95% CI 3.2–4.0) for a positive test result and 0.8 (95% CI 0.8–0.9) for a negative test result. Using perinatal death as outcome measure, the pooled likelihood ratio was 1.8 (95% CI 1.2–2.9) for a positive test result and 0.9 (95% CI 0.8–1.1) for a negative test result. In the high risk population a positive test result predicted pre-eclampsia with a pooled likelihood ratio of 2.8 (95% CI 2.3–3.4), while a negative test had a likelihood ratio of 0.8 (95% CI 0.7–0.9). For intrauterine growth retardation the pooled likelihood ratio was 2.7 (95% CI 2.1–3.4) for a positive test result and 0.7 (95% CI 0.6–0.9) for a negative result. For perinatal death the pooled likelihood ratio was 4.0 (95% CI 2.4–6.6) for a positive test result and 0.6 (95% CI 0.4–0.9) for a negative result.Conclusion Uterine artery Doppler flow velocity has limited diagnostic accuracy in predicting preeclampsia, intrauterine growth retardation and perinatal death.