Effect of Low-Dose Aspirin on the Time of Onset of Preeclampsia and Time of Delivery

Objective To determine whether low-dose aspirin (LDA) affects the time of onset of preeclampsia and the time of delivery in high-risk women. Study Design Secondary analysis of a multicenter randomized controlled trial of LDA (60 mg) in high-risk women. Quantile regression was used to identify the median gestational age at preeclampsia diagnosis and median gestational age at delivery, whereas logistic regression was used to determine the likelihood of preeclampsia-indicated delivery within 7 days. Results Total of 2,479 women were randomized and 461 developed preeclampsia. The mean gestational age at enrollment was 20 ± 4 weeks. On multivariate analysis, LDA did not affect the time of preeclampsia diagnosis (coefficient -0.4 weeks, 95% CI: -1.1 to 0.2; p = 0.2), time of delivery (coefficient 0 weeks, 95% CI: -0.3 to 0.3; p = 1), or likelihood of preeclampsia-indicated delivery within 7 days (OR = 0.8; 95% CI: 0.5-1.2; p = 0.2). In multifetal gestations, preeclampsia was diagnosed at least 1 week earlier than women with diabetes or previous preeclampsia (p < 0.05), and delivery occurred at least 2 weeks prior (p < 0.001). Conclusion LDA prophylaxis did not significantly affect time of diagnosis of preeclampsia, time of delivery, or likelihood of preeclampsia-indicated delivery within 7 days. LDA prophylaxis did not significantly affect time of diagnosis of preeclampsia, time of delivery, or likelihood of preeclampsia-indicated delivery within 7 days.