A new study out of Japan is adding to a growing body of evidence that what a mother does before and during pregnancy can have a lasting effect on her child’s development. After analyzing data on nearly 40,000 mothers and their children, researchers found that babies born to women who exercised regularly tended to reach developmental milestones earlier, particularly during the first year of life. The findings, published in the journal JAMA Network Open, are generating significant interest among medical professionals and expectant parents alike.
Dr. Rosa Cui, an assistant professor of obstetrics and gynecology at the Donald and Barbara Zucker School of Medicine at Hofstra/Northwell Health, who was not involved in the research, described the study as “intriguing” in her comments to the New York Post. She noted that it stands out as one of the first to examine the potential effects of maternal exercise specifically on the neurological development of the child. Dr. Cui emphasized that physical activity is broadly beneficial to the body in general, supporting heart health and other vital systems, while also improving both the physical and mental wellbeing of pregnant women throughout their pregnancies.
While the study does not pinpoint an exact biological mechanism behind its findings, Dr. Cui offered several theories that could help explain the connection. The first centers on how exercise affects blood vessels. When muscles heat up during physical activity, blood vessels dilate, increasing circulation throughout the body. “Because of those changes at a microscopic level, you can potentially increase blood volume, and therefore improve the delivery of nutrients, oxygen, and all the good stuff that gets to the baby in the womb through the bloodstream,” she explained. This improved supply of oxygen and nutrients during a critical window of fetal brain development could plausibly support faster neurological growth after birth.
A second theory involves inflammation. Exercise is well known to reduce inflammatory processes in the body, and lower levels of inflammation during pregnancy may create a more favorable environment for fetal development. The third possibility Dr. Cui raised is perhaps the most straightforward of all: the physical movements involved in exercise may directly stimulate the sensory neurons of the fetus while it is still in the womb, essentially giving the developing nervous system a form of early and repeated activation that could lay useful groundwork for later developmental gains.
For pregnant women wondering what kinds of exercise are safe to pursue, Dr. Cui recommends aiming for 20 to 30 minutes per day of moderate-intensity activity, which she describes as movement that feels only slightly challenging. Walking, jogging, swimming, yoga, cycling, and even strength training all fall within that recommended range. She noted that in the majority of low-risk, uncomplicated pregnancies, women can safely continue the activities they were already doing before becoming pregnant. Activities that are not recommended during pregnancy include skydiving, scuba diving, hot yoga, and anything classified as high-intensity exercise. As always, expectant mothers are encouraged to consult their doctor before starting any new fitness routine.
One of the more reassuring aspects of the study is what happened after that critical first window. The developmental benefits associated with maternal exercise were most clearly observed during the first six to twelve months of life. After that point, it became harder for researchers to isolate the influence of prenatal exercise from the many other environmental and social factors that shape a child’s growth. Notably, researchers found that enrollment in daycare by age three significantly boosted children’s communication skills, problem-solving abilities, and social interactions, suggesting that the environment children grow up in after birth plays an equally powerful role in shaping their development.
This is genuinely encouraging news for women who, due to health conditions or pregnancy complications, are unable to maintain an active routine during their pregnancies. Dr. Cui was clear that guilt has no place in this conversation. “For people who are motivated and already exercising, we see there is a benefit,” she said. “But if women cannot exercise for health or personal reasons, they should not feel guilty, because it seems like other stimuli from the child’s environment will also benefit their neurodevelopment.” Babies, she added, are “very, very adaptable,” and a few extra squats during pregnancy is unlikely to be the defining factor in who a child becomes.
The idea that a mother’s habits during pregnancy influence fetal brain development is supported by decades of research, but scientists are still working out just how profound those effects are and how long they last. Exercise during pregnancy has also been linked to lower rates of gestational diabetes and preeclampsia, meaning the benefits extend well beyond the baby. And interestingly, some animal studies have shown that offspring of physically active mothers display measurably different brain structure and function compared to those of sedentary ones, a finding that researchers believe may carry implications for human development as well.
Were you physically active during your pregnancy, and do you think it made a difference for your child? Share your thoughts in the comments.
