Preconception Low Dose Aspirin and Time to Pregnancy: Findings From the Effects of Aspirin in Gestation and Reproduction Randomized Trial

Objective: The objective was to determine the effect of preconception-initiated daily low-dose aspirin (LDA; 81 mg/day) treatment on time to pregnancy in women with a history of pregnancy loss. Design: This was a multicenter, block-randomized, double-blind, placebo-controlled trial. Participants were block-randomized by center and eligibility stratum. Setting: The study was conducted at four U.S.A. medical centers (2007–2012). Participants: Participants women aged 18–40 years actively attempting pregnancy, stratified by eligibility criteria: the “original” stratum, women with one loss <20 weeks' gestation during the previous year; and the “expanded” stratum, women with one or two previous losses of any gestational age regardless of time since loss. Intervention: Daily LDA was compared with matching placebo for up to six menstrual cycles of attempting pregnancy. Main Outcome Measure: Time to hCG detected pregnancy and clinically confirmed pregnancy, analyzed by intention-to-treat, was measured. Results: Of...