Neurodevelopment of Children Whose Mothers Were Randomized to Low-Dose Aspirin During Pregnancy

OBJECTIVE:Because low-dose aspirin is now commonly prescribed in pregnancy, we sought to assess the association between early antenatal exposure and child neurodevelopment.METHODS:We performed a noninferiority, masked, neurodevelopmental follow-up study of children between age 33 and 39 months whose mothers had been randomized to daily low-dose aspirin (81 mg) or placebo between 6 0/7 and 13 6/7 weeks of gestation through 37 weeks. Neurodevelopment was assessed with the Bayley-III (Bayley Scales of Infant and Toddler Development, 3rd Edition) and the ASQ-3 (Ages and Stages Questionnaire, 3rd Edition). The primary outcome was the Bayley-III cognitive composite score with a difference within 4 points demonstrating noninferiority.RESULTS:A total of 640 children (329 in the low-dose aspirin group, 311 in the placebo group) were evaluated between September 2021 and June 2022. The Bayley-III cognitive composite score was noninferior between the two groups (-1, adjusted mean -0.8, 95% CI, -2.2 to 0.60). Significant differences were not seen in the language composite score (difference 0.7, 95% CI, -0.8 to 2.1) or the motor composite score (difference -0.6, 95% CI, -2.5 to 1.2). The proportion of children who had any component of the Bayley-III score lower than 70 did not differ between the two groups. Similarly, the communication, gross motor, fine motor, problem-solving, and personal-social components of the ASQ-3 did not differ between groups. Maternal characteristics, delivery outcomes, breastfeeding rates, breastfeeding duration, and home environment as measured by the Family Care Indicators were similar.CONCLUSION:Antenatal low-dose aspirin exposure was not associated with altered neurodevelopmental outcomes at age 3 years.