Early initiation of low-dose aspirin for reduction in preeclampsia risk in high-risk women: a secondary analysis of the MFMU High-Risk Aspirin Study

Objective:early initiation of low-dose aspirin (lda) may reduce preeclampsia risk. we sought to determine whether lda was beneficial when initiated <17w0d, within a trial of high-risk women enrolled <26w0d.study design:secondary analysis of the maternal-fetal medicine units high-risk aspirin study, including women enrolled <17w0d, randomized to lda (60 mg day−1) or placebo with chronic hypertension (chtn, n=186), diabetes (n=191) or prior preeclampsia (n=146). the primary outcome was preeclampsia at any time in pregnancy, secondary outcomes were early preeclampsia (<34w0d), late preeclampsia (⩾34w), small for gestational age (sga; neonatal birthweight <10th %) and composite (early preeclampsia or sga). outcomes were compared by exact χ2-tests.results:baseline characteristics were similar between treatment groups. aspirin was associated with a lower rate of late-onset preeclampsia ⩾34w (17.36% vs 24.42%, p=0.047), with a 41% reduction in women with chtn (18.28% vs 31.18%, p=0.041). there were no other significant differences in the outcome.conclusion:aspirin initiated <17w0d reduced the risk for late-onset preeclampsia by 29% supporting the practice of early initiation of aspirin in high-risk women.