Physical Activity Before and During Pregnancy and Neurodevelopment in Early Childhood.

Higher prepregnancy physical activity was associated with significantly higher odds for each ASQ-3 developmental domain at 6 months of age.

• Study analyzed 38,219 mother-child pairs from the Japan Environment and Children's Study, a nationwide birth cohort.
• Maternal physical activity was assessed using the International Physical Activity Questionnaire (IPAQ) before and during pregnancy.
• Child neurodevelopment was assessed using the Ages and Stages Questionnaires, Third Edition (ASQ-3) at 6-month intervals from 6 months to 3 years of age.
• Five developmental domains were evaluated: communication, gross and fine motor skills, problem solving, and personal-social.
• Multivariable logistic regression was used to assess associations.

Higher midpregnancy physical activity was associated with significantly higher odds for gross motor, fine motor, and problem-solving domains in children.

• Gross motor domain: OR 1.18 (95% CI, 1.06–1.33).
• Fine motor domain: OR 1.60 (95% CI, 1.37–1.86).
• Problem-solving domain: OR 1.23 (95% CI, 1.10–1.38).
• These associations were observed at or around 6 months to 1 year of age.
• Higher midpregnancy activity was not associated with higher odds of any ASQ domain at 3 years of age.

Higher prepregnancy physical activity was associated with higher odds for the problem-solving domain at 3 years of age, with no association found for any other domain at that age.

• Problem-solving domain at 3 years: OR 1.16 (95% CI, 1.01–1.34).
• No significant association was found between prepregnancy activity and communication, gross motor, fine motor, or personal-social domains at 3 years.
• Higher midpregnancy activity was not associated with higher odds of any ASQ-3 domain at 3 years of age.

The study cohort consisted of 38,219 mother-child pairs after applying exclusion criteria to an initial dataset of 104,062 records.

• 65,843 records were excluded due to missing data or guideline-based criteria.
• Maternal mean (SD) age was 31.1 (4.8) years.
• 19,429 (50.8%) of included children were male.
• Mother-child pairs were recruited and enrolled between January 24, 2011, and March 31, 2014, with child follow-up from birth to 3 years of age.
• The analysis was conducted between June 24, 2024, and June 30, 2025.

The association between maternal physical activity and child neurodevelopment was particularly pronounced for motor function between 6 months and 1 year of age.

• Both prepregnancy and midpregnancy physical activity showed associations with motor domains in early infancy.
• The fine motor domain showed the strongest association with midpregnancy activity (OR 1.60; 95% CI, 1.37–1.86).
• Associations diminished by 3 years of age, with only problem-solving remaining significant for prepregnancy activity.
• Authors noted that further investigations are required to find the physiological mechanisms explaining how maternal physical activity affects child neurodevelopment.