W3.1 The epidemiology of preeclampsia: use of population data for research

Abstract

W5.1 – Table 1. Comparison of outcomes in Cochrane Reviews and this systematic review Outcome Cochrane Review RR (95% CI) This systematic review Odds Ratio (95% CI) MgS04 None/other anti convulsant Preeclampsia (MgS04 vs none) Death RR 0.54 (0.26,1.10) N/A 0/214 7/383 Seizure RR 0.41 (0.29,0.58) N/A 2.7/10000 4.9/10000 5%£ 1.6%* Eclampsia (MgS04 vs other) Death RR 0.60 (0.36,1.00) = 0.31 (0.01, 8.28) to 0.80 (0.03, 20.62) 0-8.6% 2.5-16% RR 0.50 (0.24,1.05) Recurrent seizure RR 0.45 (0.35,0.58) = 0.30 (0.06, 1.62) to 1.07 (0.09, 12.71) 4.8-12.5% 6-32% RR 0.31 (0.20,0.47) Stillbirth RR 0.89 (0.63,1.26) = 0.43 (0.08, 2.37) to 0.69 (0.07, 7.19) 6-15% 3-23% RR 0.83 (0.61,1.13) Neonatal death RR 1.34 (0.84,2.14) = 0.62 (0.09, 4.32) to 1.07 (0.17, 6.56) 12% 12-22% RR 0.95 (0.59,1.53) CI = confidence interval, =diazepam, phenytoin, £high risk unit, *excluding MgS04 recipients. systematic review of randomised trials, involving over 11,000 women with pre-eclampsia, the use of magnesium sulphate compared with placebo or no anticonvulsant more than halved the risk of eclampsia. Antenatal magnesium sulphate has now been evaluated for fetal, infant and childhood neuroprotection prior to very preterm birth. The Cochrane systematic review included five randomised trials, involving over 4400 babies. In women at risk of very preterm birth, antenatal magnesium sulphate compared with placebo reduced the risk in the fetus, infant or risk of death or cerebral palsy, or cerebral palsy alone. The research evidence-base for the use of magnesium sulphate for neuroprotection of the mother and neonate has been used to prepare and update clinical practice guidelines worldwide. The clinical challenge is to ensure optimal, local implementation with removal of any research knowledgeimplementation barriers. The completed systematic reviews and clinical practice guidelines on the use of magnesium sulphate for neuroprotection highlight on-going research gaps and make recommendations for further research. These should become our priority for research, whether a health professional, consumer, policy maker or funder. W5.1 Maternal and infant outcomes on magnesium sulphate for preeclampsia/eclampsia: a systematic review comparing outcomes within trials with outcomes outside of trials Sarah McDonald1, Nancy Dzaja2, Olha Lutsiv3, Lelia Duley4. 1Department of Obstetrics & Gynecology, Division of Maternal-Fetal Medicine and Department of Diagnostic Imaging, and Department of Clinical Epidemiology & Biosatistics, McMaster University, Hamilton, Ontario, Canada; 2Department of Obstetrics & Gynecology, McMaster University, Hamilton, Ontario, Canada; 3Health Sciences, McMaster University, Hamilton, Ontario, Canada; 4University of Leeds, Centre for Epidemilogy and Biostatistics, Genetics, Health and Therapeutics, West Yorkshire, UK, UK Background: Eclampsia remains a leading cause of maternal mortality worldwide. Randomized trials have shown MgS04 reduces seizures in both preeclampsia and eclampsia, with trends towards decreases in mortality. It has been argued that outcome in trials may not always reflect outcome in similar situations outside of trials. Aim: To assess whether outcomes for women with preeclampsia and eclampsia treated with MgS04 outside of randomized trials differs from those within. Methods: We performed a systematic review of cohort, before-and-after and serial cross-sectional studies in 1) preeclamptic women who received either MgS04 or no anticonvulsant or 2) eclamptic women who received either MgS04 or another anticonvulsant. Primary outcomes were death (maternal, fetal, neonatal) or eclampsia/further seizures. Embase and Medline were searched from 1990 onwards (5 years before the Collaborative Eclampsia Trial publication). Results: Ten studies met inclusion criteria, mainly based in academic centres in Bangladesh, India, Pakistan, Saudi Arabia and Turkey (see Table 1 below). Conclusions: Outcomes outside RCTs are comparable to those within. This supports the view that results of RCTs are a reliable basis for clinical care.