Aspirin for the Prevention of Pre-eclampsia in Twin Pregnancies: and Individual Participant Data (IPD) Meta-analysis

Low-dose aspirin effectively prevents preterm pre-eclampsia in singleton pregnancies (ASPRE trial, Rolnik et al. NEJM 2017). We are currently updating the 2007 PARIS individual participant data (IPD) meta-analysis to further investigate the importance of dose and initiation timing in singletons. The beneficial effect of aspirin in preventing pre-eclampsia in twin pregnancies, however, remains unclear. Twin pregnancies are at a significantly higher risk of pre-eclampsia, with ongoing twin pregnancies being 8-9 times more likely to develop pre-eclampsia compared to their singleton counterparts at the same gestational age. Although obstetric institutions often recommend the prescription of aspirin to all twin pregnancies, the disease mechanism may differ in twins (for example, due to larger placental mass), and the evidence of a beneficial effect of aspirin in twin pregnancies is lacking and mainly based on small studies. We plan to further investigate the effects of aspirin in twin pregnancies using individual participant-data meta-analysis from previous randomised controlled trials and the ongoing large ASPRE-Twins trial.