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  • Study: Mothers Who Exercise During Pregnancy Give Their Infants a Motor Skills Boost

    In this review: Effects of Aerobic Exercise During Pregnancy on 1-Month Infant Neuromotor Skills
    (Medicine and Science in Sports and Exercise, August 2019)

    The message
    Infants of mothers who engaged in aerobic exercise during pregnancy tend to show better motor development at 1 month compared with infants of nonexercising mothers, according to authors of a new study. The researchers believe that aerobic exercise during pregnancy could be a hedge against childhood overweight and obesity.

    The study
    Researchers analyzed data from 60 healthy mothers (ages 18 to 35, with an average age of 30) and their infants. During their pregnancies, 33 women participated in 45-50 minutes of supervised aerobic exercise, 3 days a week. The remaining 27 women in the control group were asked to engage in a 50-minute supervised stretching and breathing program 3 days a week, but were otherwise advised to continue with "normal" activities. The infants of both groups were then evaluated for motor skills development at 1 month using the Peabody Developmental Motor Scales, second edition (PDMS-2), a tool that tests reflexes, locomotion, and a child's ability to remain stationary. The measure also provides a composite score, known as the Gross Motor Quotient (GMQ).

    APTA member Amy Gross McMillan, PT, PhD, was lead author of the study.

    Findings

    • The PDMS-2 scores, expressed as percentiles, were higher for the exercise group in the areas of stationary (45.5 compared with 39.5 for the control group), locomotion (55.7 compared with 50), and overall GMQ (56.3 compared with 52.5). They were lower in the reflex category (63.1 for the exercise group, compared with 66.2 for the control).
    • In the control group, male infants performed better than female infants in most tests—a finding that researchers expected given what's known about the role of testosterone in male infant development. However, in what authors describe as an "intriguing" finding, female infants in the exercise group tended to close that gap and even outperformed males, albeit slightly, in reflex, stationary, and GMQ scores.
    • There were no significant between-group differences in maternal age, BMI, number of live children, or education; and all infants included in the study were born healthy and full-term with no congenital abnormalities.
    • In the exercise group, compliance averaged 83%, with 81% of the exercising mothers reaching at least 70% compliance during pregnancy.

    Why it matters
    With childhood obesity and overweight rates continuing to rise, the pressure is on to promote healthy rates of physical activity (PA). Authors of this study point to previous research that links better motor skills in infancy to higher rates of PA through childhood and adulthood, and write that "the promotion of exercise during pregnancy may positively impact childhood health outcomes."

    More about the findings
    Authors aren't sure what exactly is happening through aerobic exercise in pregnancy, but they speculate that it may have to do with the release of growth hormone and intrauterine growth factor-1, which do not cross the placenta but can increase the supply of nutrients to the fetus. Additionally, they believe that the improved blood flow and oxygenation associated with aerobic exercise may also contribute to the differences.

    Keep in mind…
    The research involved only healthy women and didn't control for other factors that contribute to mother and infant health, including sleep, diet, sedentary behavior, occupation, and the infant's environment after birth.

    Research-related stories featured in PT in Motion News are intended to highlight a topic of interest only and do not constitute an endorsement by APTA. For synthesized research and evidence-based practice information, visit the association's PTNow website.