The following is a summary of “Comparison of two aspirin doses for the prophylaxis of pre-eclampsia in twin pregnancy: a multicentre retrospective study with propensity score matching,” published in the January 2025 issue of Obstetrics and Gynecology by Zorzato et al.

This study investigates the optimal dosage of aspirin for preventing preeclampsia and hypertensive disorders of pregnancy (HDP) in twin pregnancies, addressing the current lack of consensus on the effective prophylactic dosage. While some medical guidelines advocate for daily doses of 75-81 mg, others recommend 160 mg, but robust randomized controlled trials comparing these dosages are scarce. Moreover, research on the appropriate aspirin dosage for twin pregnancies remains limited. This international multicenter retrospective cohort study, conducted across three European centers, included 1,907 twin pregnancies with live fetuses at 13 weeks of gestation. Exclusion criteria were fetal malformations, twin-twin transfusion syndrome, twin anemia polycythemia sequence, twin reversed arterial perfusion sequence, vanishing twin syndrome before 13 weeks, and loss to follow-up. 

The participants were divided into three groups: no aspirin (1,423 cases), daily 80-100 mg aspirin (212 cases), and daily 160 mg aspirin (272 cases). The primary outcomes were the incidence of preeclampsia and HDP, with secondary outcomes including small-for-gestational age, postpartum hemorrhage >1000 mL, antenatal bleeding of obstetrical origin, thrombocytopenia, miscarriage, intrauterine fetal demise (IUFD), neonatal death, and gastritis. Propensity score matching and multivariate analyses adjusted for maternal age, body mass index, race, parity, history of preeclampsia, chronic hypertension, diabetes mellitus, thrombophilia, spontaneous conception, and twin type to balance the study groups (absolute standardized difference <15% for most variables, except for age and thrombophilia). 

Cox regression models indicated that the 160 mg aspirin group experienced a significant reduction in the hazard ratio (HR) for preeclampsia (HR 0.63) and HDP (HR 0.56) compared to the lower dosage and non-aspirin groups. The 80-100 mg dosage did not effectively lower the HR below 1. Additionally, the higher dosage notably reduced the risk of preeclampsia before 34 weeks of gestation without a significant increase in aspirin-related complications such as bleeding or thrombocytopenia. The findings suggest that a daily dosage of 160 mg aspirin may provide superior prophylactic benefits in twin pregnancies without elevating the risk of adverse outcomes. Further, longitudinal studies are recommended to assess long-term implications and optimize dosage strategies.

Source: sciencedirect.com/science/article/abs/pii/S0002937825000067