Maternal Sedentary Behavior and Physical Activity across Pregnancy and Early Childhood Growth

Evidence suggests in utero exposures are related to lifespan health of the offspring. Whether maternal activity profile during pregnancy impacts offspring health remains unknown. This follow-up study recruited mothers with objectively measured sedentary behavior (SED) and moderate-to-vigorous intensity physical activity (MVPA) from a previous cohort study. Maternal activity was analyzed across pregnancy (trajectory groups) and continuously by trimester. Offspring anthropometrics up to 24 months were abstracted from medical records (n = 62). Outcomes included childhood growth rate (incremental rate of BMI z-score change up to 24 months) and rapid growth (increased BMI z-score >0.67 at 12 months). Associations of maternal activity with growth rate were examined using mixed linear models and rapid growth using generalized linear models. Forty percent of participants were in the high SED and 20% in the high MVPA trajectories during pregnancy. Higher SED, across pregnancy [slope (95% confidence interval; CI): 0.080 (0.024-0.061) ΔBMI z-score/month] and in the first trimester [standardized beta; std β (95% CI): 0.017 (0.007-0.026)], was related to accelerated growth rate. Higher MVPA, in the second and third trimesters, was associated with accelerated growth rate [std β (95% CI): trimester 2: 0.013 (0.002-0.024) and trimester 3:0.011 (0.003-0.020)] and greater risk of rapid growth [risk ratio (95% CI): trimester 2: 1.25 (1.009-1.555) and trimester 3: 1.25 (1.056-1.475)]. These findings add to growing evidence on the deleterious effects of high SED during pregnancy. The increased risk for accelerated growth with higher MVPA elicits further investigation. Overall, maternal activity profile shows promise as a modifiable behavior to improve intergenerational health.