Patterns of physical activity and sedentary behavior before and during pregnancy and cardiometabolic outcomes.

Objective: To assess how physical activity and sedentary behavior change from pre-pregnancy to pregnancy, and if pre-pregnancy and pregnancy physical activity and sedentary behavior are related to gestational weight gain, blood pressure, or blood glucose across pregnancy.

Design: Secondary analysis of two prospective cohort studies.

Setting: Prenatal research centers in Pittsburgh, PA and Iowa City, IA.

Participants: Pregnant individuals (n=131), 18-45 years old, of any BMI, with no medical condition limiting physical activity or use of hypertension/diabetes medications.

Methods: Participants self-reported physical activity and sedentary behavior pre-pregnancy and in each trimester using validated questionnaires. Blood pressure, blood glucose, and weight were obtained from study visits and/or electronic medical records. Multivariable regression examined associations between pre-pregnancy, trimester-specific, and changes in physical activity and sedentary behavior with weight gain and blood pressure outcomes in each trimester, and blood glucose in the second trimester.

Results: Compared to pre-pregnancy, physical activity was lower in each trimester, and sedentary behavior was higher in each trimester (p<0.05). Increasing physical activity from pre-pregnancy levels was associated with lower first trimester SBP (p<0.05). Unexpectedly, higher pre-pregnancy physical activity was associated with higher SBP in the first trimester (p=0.02) and higher weight gain in the third trimester (p=0.02). Higher and increasing sedentary behavior was associated with greater weight gain in the third trimester (p=0.03).

Conclusion: Future research should investigate the opportune time (before or during pregnancy) to deliver behavior modification interventions that could prevent excessive gestational weight gain or elevated blood pressure to improve maternal health outcomes.