Preconception low-dose aspirin is well-tolerated by women trying to conceive, women who become pregnant, and by their fetuses and neonates, although rare but serious complications cannot be ruled out. This according to a study of 1,228 US women aged 18 to 40 years and with a history of 1 to 2 pregnancy losses trying to conceive. Participants were randomized to daily low-dose aspirin (81 mg, n=615) or placebo (n=613) and were followed for up to 6 menstrual cycles or through gestation if they became pregnant. Researchers found:

• The proportion of women with at least 1 possible aspirin-related symptom during the trial was similar between treatment arms, as was the proportion with at least 1 emergency care visit.

• Maternal complications were evenly distributed by treatment arm with the exception of vaginal bleeding, which was more common in the low-dose aspirin arm (22% vs 17%).

• The distribution of fetal and neonatal complication—which included 3 stillbirths, 3 neonatal deaths, and 10 neonates with birth defects—was similar between treatment arms.

Citation: Ahrens KA, Silver RM, Mumford SL, et al. Complications and safety of preconception low-dose aspirin among women with prior pregnancy losses. [Published online ahead of print March 7, 2016]. Obstet Gynecol. doi:10.1097/AOG.0000000000001301.