12-05-2025
Mom's Hormone Levels While Pregnant Linked to Kids' Physical Activity
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A mother's hormones during pregnancy can negatively affect her child years later, a new study has cautioned.
Boys whose mothers had polycystic ovarian syndrome (PCOS) or elevated testosterone levels during the third trimester of pregnancy appear less physically active by age seven.
The effect wasn't seen in girls, but girls exposed to higher testosterone levels in the womb were found to have lower muscle strength at age seven.
The study, led by researchers at Odense University Hospital and the University of Southern Denmark, analyzed data from 695 pregnant women and their children.
Using an accelerometer—a device that tracks changes in movement—the team measured the physical activity of the seven-year-olds and discovered boys born to mothers with PCOS were less active, particularly on weekends, compared to their peers.
Relaxed boy lies on couch playing online virtual video game, use app on internet on smartphone.
Relaxed boy lies on couch playing online virtual video game, use app on internet on smartphone.
Dima Berlin
Additionally, this reduced activity wasn't due to factors like birth weight or the mother's pre-pregnancy body mass index (BMI).
Instead, it seems directly tied to higher maternal testosterone levels—a hormone that typically spikes during pregnancy and is even higher in women with PCOS.
Camilla Viola Palm, the study's lead author, explained that while previous research often relied on questionnaires to gauge child activity, this study's use of objective movement tracking makes its findings especially compelling.
"Maternal pre-pregnancy health conditions, like PCOS, may transgenerationally affect the physical activity of boys," she said.
Palm also warned that a drop in physical activity, especially on weekends when children have more free time, could set the stage for future obesity and cardiovascular disease (CVD) in these boys.
For girls, higher testosterone exposure during pregnancy didn't impact their activity levels but did result in lower muscle strength, which may also have long-term health consequences.
This is the latest in a series of findings by the team, which previously showed that boys exposed to higher prenatal testosterone had more body fat by age seven and lower grip strength by age five.
The researchers are now planning to follow these children into adolescence to see if the effects persist, potentially impacting obesity, blood pressure and type 2 diabetes risk.
"There is only little data on boys regarding PCOS-related metabolic and CVD risk, as PCOS is a female condition by definition," Palm said.
The research also suggests the effects of PCOS and the hormone imbalances it causes, may extend to the next generation.
The research was presented at the first Joint Congress between the European Society of Pediatric Endocrinology and the European Society of Endocrinology.
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Reference
Palm, C. V., Grøntved, A., Christesen, H., Glintborg, D., & Andersen, M. (2025, May 10–13). Habitual activity and muscle strength in children of mothers with, or without, polycystic ovary syndrome. [Conference presentation]. Joint Congress of
ESPE and ESE 2025, Copenhagen, Denmark.
