Paris Collaboration: Antiplatelets to Prevent Pre-Eclampsia. A Review Using Individual Patient Data - Maternal Outcomes.

Abstract

PARIS Collaboration: antiplatelets to prevent pre-eclampsia. A review using individual patient data (IPD) - maternal outcomes. Askie LM (1), Henderson-Smart DJ (2), Duley L (3), Stewart L (4), Showell M (2), on behalf of the PARIS Collaboration. (1) NHMRC Clinical Trials Centre, University of Sydney, Australia; (2) Centre for Perinatal Health Services Research, University of Sydney, Australia; (3) Resource Centre for Randomised Trials, University of Oxford, UK; (4) Medical Research Council Clinical Trials Unit, London, UK Background: The Cochrane Systematic Review of antiplatelet agents, principally low dose aspirin, using aggregate data from 51 trials (36,500 women) demonstrates that these confer small to moderate, but nonetheless important, reductions in risk of pre-eclampsia, baby death and preterm delivery. To understand more about how to target antiplatelet therapy to maximise benefit for women and their infants, we conducted a systematic review and series of metaanalyses using data from individual women in each trial. This abstract presents results for the women. Methods: Randomised trials comparing antiplatelets with placebo or no antiplatelet, during pregnancy, were included. Participating trialists joined the PARIS (Perinatal Antiplatelet Review of International Studies) Collaboration. This group developed and agreed a protocol, specifying the dataset to be collected and meta-analysis plan. Data were obtained for individual women and infants and checked thoroughly. Outcome and subgroup definitions were applied consistently across trials. Main maternal outcomes were pre-eclampsia and whether a serious adverse outcome was experienced in the pregnancy. Secondary outcomes included several measures of maternal morbidity. IPD allowed more powerful sub-group analyses than are possible with aggregate data. These included gestation at randomisation and risk factors such as hypertension, previous history of pre-eclampsia or SGA infants, diabetes, renal or automimmune disease and maternal age. Trial-level characteristics including type of antiplatelet and dose were also investigated. Sensitivity analyses explored trial size, quality, and method of defining pre-eclampsia. Results: IPD were obtained and analysed for 36 trials (35,796 women), representing 90% of the worldwide randomised data addressing this question. Conclusions: Results, which will provide the most comprehensive and reliable assessment of the use of antiplatelet agents in the prevention of pre-eclampsia and its complications, will be discussed within the PARIS Collaborative Group in June 2006 and presented publicly for the first time at ISSHP 2006.