TOPLINE:

Maternal physical activity before and during pregnancy is associated with improved neurodevelopmental outcomes in children, particularly motor function between age 6 months and 1 year. Among 38,219 mother-child pairs, higher prepregnancy activity showed more than 30% higher odds for enhanced gross motor skills at 6 months, while midpregnancy activity demonstrated 60% higher odds for fine motor development.

METHODOLOGY:

• Researchers analyzed data from the Japan Environment and Children's Study, a nationwide birth cohort that recruited approximately 100,000 mother-child pairs between January 2011 and March 2014, with 38,219 pairs included in the final analysis after exclusions.
• Maternal physical activity levels were assessed using the International Physical Activity Questionnaire (IPAQ) at two timepoints: before pregnancy and during midpregnancy (16-27 weeks’ gestation), with physical activity classified into three categories based on metabolic equivalent minutes per week.
• Child neurodevelopment was evaluated using the Ages and Stages Questionnaires, Third Edition (ASQ-3) at 6-month intervals from 6 months to 3 years of age, assessing five developmental domains: communication, gross motor skills, fine motor skills, problem solving, and personal-social skills.
• Multivariable logistic regression models were used to examine associations between maternal physical activity and child neurodevelopment, adjusting for gestational age, birth weight, maternal age, prepregnancy BMI, predelivery BMI, group childcare attendance, siblings, family income, and parental education.
• Analysis was conducted between June 2024 and June 2025, with participants excluded if they had missing ASQ-3 data at any timepoint, maternal BMI outliers of ±5 standard deviations, or maternal physical activity outliers according to IPAQ guidelines.

TAKEAWAY:

• Higher prepregnancy physical activity was associated with higher odds across all ASQ-3 domains at 6 months, with particularly strong associations in communication (odds ratio [OR] vs no activity, 1.61; 95% CI, 1.04-2.45), gross motor skills (OR vs no activity, 1.37; 95% CI, 1.22-1.54), and fine motor skills (OR vs no activity, 1.32; 95% CI, 1.13-1.54) domains.
• Midpregnancy physical activity showed associations with higher odds in gross motor skills (moderate to high activity vs no activity OR, 1.18; 95% CI, 1.06-1.33), fine motor skills (moderate to high activity vs no activity OR, 1.60; 95% CI, 1.37-1.86), and problem solving (moderate to high activity vs no activity OR, 1.23; 95% CI, 1.10-1.38) domains at 6 months.
• At 3 years of age, maternal physical activity showed limited associations, with only prepregnancy activity linked to higher odds in the problem-solving domain (OR, 1.16; 95% CI, 1.01-1.34), while midpregnancy activity showed no association with any ASQ-3 domain.
• More midpregnancy physical activity was associated with reduced rates of preterm birth (4.1% overall, with 5.5% in no activity group vs 3.3% in high activity group; P < .001) and low birth weight of < 5.5 lb (8.8% in no activity group vs 7.3% in high activity group; P < .001).

IN PRACTICE:

“In this cohort study of mother-child pairs, maternal physical activity before and during pregnancy was associated with child neurodevelopment, particularly for motor function between 6 months and 1 year of age. Further investigations are required to find the physiological mechanisms explaining how maternal physical activity affects child neurodevelopment,” wrote the authors of the study.

SOURCE:

The study was led by Io Kumasaka, MD, Department of Development and Environmental Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan, and Chiharu Ota, MD, PhD, Department of Pediatrics, Tohoku University Hospital, Sendai, Japan. It was published online March 3 in JAMA Network Open.

LIMITATIONS: 

Selection bias is a concern as the requirement to complete numerous questionnaires may have recruited more health-conscious participants, and excluding those with missing ASQ-3 data at any timepoint reduced the original sample by more than half, potentially selecting for highly engaged participants with higher socioeconomic status. 

Maternal physical activity levels may be imprecise due to reliance on self-reported questionnaires, which allows subjective interpretation and recall bias, potentially overestimating or underestimating exercise intensity and duration. Reverse causation cannot be ruled out, as mothers with pregnancy complications or threatened preterm labor may have reduced their activity due to medical advice, complicating the determination of causality. The generalizability of these findings may be limited to populations with similar socioeconomic and cultural backgrounds as the Japanese cohort studied.

DISCLOSURES:

This study received funding from Japan’s Ministry of Environment. The authors reported no relevant financial relationships.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.