Maternal Cardiovascular Health During Pregnancy and Offspring Developmental Delay.

Importance: Developmental delay affects daily living, social functioning, and mental health. Maternal cardiovascular health (CVH) during pregnancy may indicate an adverse intrauterine environment, but its association with developmental delay is unclear. Objective: To examine the association between maternal CVH during pregnancy and developmental delay in offspring at 4 years of age. Design, Setting, and Participants: This cohort study enrolled patients between July 19, 2013, and March 31, 2017, with 5 years of follow-up, at obstetric hospitals and clinics in Miyagi Prefecture, Japan. Participants included eligible mother and offspring pairs enrolled in the Tohoku Medical Megabank Project Birth and Three-Generation Cohort Study. Offspring were followed up until age 4 years. Data analyses were conducted from November 12, 2024, to March 24, 2026. Exposure: Maternal CVH during pregnancy, which was assessed using Life's Essential 8 metrics (diet, physical activity, nicotine exposure, sleep health, body mass index, blood lipids, blood glucose, and blood pressure). Each metric was scored on a scale of 0 (least favorable) to 100 (most favorable), and these scores were used to categorize mothers as having high (80-100), moderate (50-79), or low (0-49) CVH. Main Outcomes and Measures: Developmental delay at age 4 years, which was evaluated by the mother using the validated Japanese version of Ages and Stages Questionnaire, Third Edition. This instrument has 5 domains: communication, gross motor, fine motor, problem solving, and personal-social skills. Domain-specific delay was defined as 2 or more SDs below the mean score, and developmental delay in total was defined as delay in 1 or more of the 5 domains. Results: Among 19 160 eligible mother and offspring pairs, 8238 (43.0%) were analyzed. Offspring were assessed at a mean (SD) age of 4.1 (0.2) years and included 4299 males (52.2%). Among mothers with high, moderate, and low CVH, 154 (8.8%), 763 (12.1%), and 33 (16.8%), respectively, had offspring with developmental delay in total. Compared with high CVH, moderate (risk ratio [RR], 1.30; 95% CI, 1.09-1.54) and low (RR, 1.62; 95% CI, 1.11-2.36) CVH during pregnancy were associated with developmental delay in total. Low CVH was associated with higher prevalence of developmental delay across all 5 domains, with personal-social domain having the largest effect size (RR, 2.23; 95% CI, 1.23-4.07; P for trend = .002) and communication domain having the smallest effect size (RR, 1.40; 95% CI, 0.69-2.85; P for trend = .03). Conclusions and Relevance: In this cohort study of mother and offspring pairs in Japan, better maternal CVH during pregnancy was associated with a lower risk of offspring developmental delay at age 4 years.