Prenatal Testosterone Levels Influence Physical Activity and Muscle Strength in Children

Recent research has unveiled significant findings regarding the impact of prenatal testosterone exposure on children's physical development. Presented at the inaugural Joint Congress of the European Society of Pediatric Endocrinology and the European Society of Endocrinology, the study indicates that boys born to mothers with polycystic ovary syndrome (PCOS) or elevated testosterone levels during the third trimester exhibit lower physical activity levels by the age of seven. Conversely, girls whose mothers had higher testosterone during pregnancy showed decreased muscle strength at the same age.

Testosterone is essential for male fetal development and is believed to influence neurodevelopment and muscle strength in children as they grow. While testosterone levels typically rise during pregnancy, they remain similar for mothers expecting boys or girls. However, women with PCOS, a common reproductive health disorder affecting approximately 13% of women of reproductive age, tend to have higher testosterone levels.

The research team from Odense University Hospital and the University of Southern Denmark previously identified that children at age five demonstrate reduced grip strength if their mothers had higher testosterone levels during the third trimester. In this latest study, they analyzed testosterone data from 695 pregnant women, both with and without PCOS, and assessed the physical activity and muscle strength of their 695 children at age seven, utilizing data from the Odense Child Cohort.

Findings revealed that boys born to mothers with PCOS were notably less active on weekends compared to their peers. The correlation between maternal testosterone and reduced physical activity in boys was found to be independent of factors such as birth weight or maternal pre-pregnancy body mass index (BMI). In contrast, girls exposed to elevated testosterone while in the womb exhibited lower muscle strength at age seven.

Dr. Camilla Viola Palm, the lead researcher, emphasized the unique methodology of this study, which objectively measured children's physical activity using accelerometers over a week, a departure from previous studies that relied on questionnaires. This research aims to shed light on how maternal health conditions like PCOS may transgenerationally influence boys' physical activity patterns, potentially increasing their risk for obesity and cardiovascular disease later in life.

Despite PCOS being classified as a female condition, the study highlights a gap in data regarding the metabolic and cardiovascular risks associated with it in boys. The research team plans to further investigate whether children exposed to PCOS and elevated testosterone levels continue to show reduced physical activity as they transition into adolescence. Future studies will explore the long-term health implications, including obesity, blood pressure, and type 2 diabetes, in these children, leveraging the comprehensive data available from the Odense Child Cohort, which tracks participants from birth to 18 years of age.