For years, doctors have encouraged women to stay active during pregnancy because of its well-established benefits: it lowers the risk of gestational diabetes, supports healthy weight gain, improves cardiovascular fitness, boosts mood, and may even make labour and recovery easier.
But could exercise during pregnancy also benefit a baby's developing brain?
A study published in JAMA Network Open suggests maternal physical activity may be associated with improved early neurodevelopment in children, particularly during infancy.
Researchers from Japan analysed data from the Japan Environment and Children's Study, a cohort study funded by Japan's Ministry of the Environment.
Their study analysed data from 38,219 mother-child pairs, examining mothers' physical activity levels before pregnancy and during mid-pregnancy, and comparing them with their children's developmental milestones from six months to three years of age.
Maternal physical activity was assessed using a standardised International Physical Activity Questionnaire, while child neurodevelopment was assessed using the Ages and Stages Questionnaires, Third Edition (ASQ-3) at 6-month intervals from six months to three years of age.
The questions evaluated five domains, including communication, gross motor skills, fine motor skills, problem-solving and personal-social development.
Among the 38,219 mother-child pairs, multivariable logistic regression showed that higher maternal physical activity was associated with early child neurodevelopment.
Achieving developmental scores
Higher pre-pregnancy activity was associated with significantly higher ASQ-3 domain scores at six months of age, and higher mid-pregnancy activity was associated with a greater likelihood of achieving age-appropriate developmental scores in the gross motor, fine motor, and problem-solving domains.
Importantly, higher pre-pregnancy activity was associated with higher odds for the problem-solving domain at three years of age. Meanwhile, there was no association with any other domain.
The researchers found that mothers who were more physically active before and during pregnancy were more likely to have infants with stronger developmental scores, particularly during the first year of life.
The most consistent improvements were seen in:
> Gross motor skills, such as crawling and walking
> Fine motor skills, which include grasping and hand-eye coordination
> Problem-solving abilities during infancy
Interestingly, by the time children reached three years of age, the only developmental area that remained associated with higher maternal physical activity before pregnancy was problem-solving.
This being an observational cohort study, meaning researchers observed natural differences between families rather than assigning women to exercise or not exercise.
Women who exercise regularly often differ from less active women in many ways. They may have healthier diets, better sleep, higher educational attainment, different healthcare access, or other lifestyle factors that also influence child development.
Although the researchers adjusted for many of these variables, it's impossible to account for every potential confounding factor.
Because of this, the study demonstrates an association, not proof of cause and effect.
According to scientists and many hypotheses, regular physical activity during pregnancy may help,
> Improve blood flow to the placenta
> Enhance oxygen and nutrient delivery to the foetus.
> Reduce inflammation
> Improve maternal metabolic health> Lower stress levels
> Promote the release of growth factors that support brain development
These biological mechanisms are plausible, but researchers emphasise that they remain under investigation.
The importance of staying active
Staying active during pregnancy remains one of the healthiest choices for most women with uncomplicated pregnancies.
This study adds to evidence suggesting that maternal physical activity may be associated with better early problem-solving skills in children.
The 2018 update to the United States Department of Health and Human Services Physical Activity Guidelines for Americans recommends that women without contraindications engage in at least 150 minutes of moderate-intensity aerobic activity per week during pregnancy and the postpartum period.
Walking, swimming, stationary cycling, prenatal yoga, and strength training with appropriate modifications are all commonly recommended options.
This large study adds to growing evidence that maternal physical activity may support early neurodevelopment, particularly motor skills during infancy.
However, it does not prove that exercise alone during pregnancy improves intelligence.
The strongest message remains the simplest: exercise during pregnancy is already known to benefit maternal health, and this research suggests those benefits may extend, at least in part, to a child's early development.
Future studies and longer-term follow-up will help determine whether these early developmental advantages associated with physical activity translate into lasting cognitive or mental health benefits. – dpa
