What is the Influence of Prenatal Physical Activity on Body Weight, BMI, and Health Behavior in Seven‐Year‐Old Children?

Objectives To investigate the effects of a prenatal exercise intervention on offspring body weight, body mass index (BMI), and lifestyle variables at 7 years of age. Methods Out of 105 physically inactive participants initially randomized to either a physical activity intervention or control group, 80 women and their children (76.2%) participated in this follow‐up study. The intervention consisted of intensive physical activity counseling and supervised, group‐based moderate‐intensity exercise sessions during the second and third trimesters of pregnancy, while the control group received standard prenatal care only. Data were collected via a standardized telephone interview with the mother and included the offspring’s body weight and height, physical activity level, sports participation, and adherence to general health recommendations regarding screen time and diet. Differences between groups were examined using two‐sided independent sample t ‐tests or chi‐squared tests as appropriate. Results Mean BMI was similar in both groups (intervention group: n = 40; control group: n = 40), but the intervention group had fewer children with overweight/obesity (1 vs. 4) and underweight (3 vs. 6) than the control group. There was a nonsignificant trend toward increased physical activity among the offspring of the intervention group compared with the control group. This was reflected in a higher number following guidelines (≥ 60 min of daily moderate‐to‐vigorous physical activity [MVPA] according to WHO recommendations) (97.5% vs. 87.5%), number of bouts of MVPA per week (6.4 ± 3.8 vs. 5.8 ± 2.3), and daily hours of MVPA in both summer and winter seasons (2.4 ± 1.3 vs. 2.2 ± 1.3 and 1.6 ± 1.0 vs. 1.4 ± 1.0). The intervention group also reported higher rates of active school transportation than the control group (72.5% vs. 57.5%). No differences were observed in sedentary screen time and diet between the groups. Conclusions Our results suggest that the intervention may have positively influenced the BMI status and physical activity levels of the offspring.