Monitoring Movement and Health Study

The investigators will study sedentary behavior (SED) across pregnancy in young women. We hypothesize that SED will increase across pregnancy and that higher SED will be related to worse cardiovascular health, specifically elevated blood pressure (BP) and excessive gestational weight gain (GWG). Pregnancy is a biologically relevant period during which CVD risk factors may develop or worsen, contributing to future CVD. Pregnant women also spend most of their day sedentary, which is defined as too much sitting as distinct from too little exercise. SED has emerged as a risk factor, independent from moderate-to-vigorous physical activity (e.g., exercise), for elevated BP, obesity, diabetes, CVD, and mortality in general populations, but there are no recommendations for SED during pregnancy and few studies evaluate SED across pregnancy. These few studies are limited by small sample size, lack of repeated measures across trimesters, suboptimal SED assessment methodology, and a failure to link with clinical outcomes (e.g., BP, GWG). The investigators will address these gaps in a prospective study that will measure SED in 130 pregnant women across three trimesters using state-of-the-art objective activity monitors capable of measuring min-by-min activity by both intensity and posture. We will also measure BP and GWG during each trimester and, further, will link to and abstract all prenatal clinic weights and BPs, glucose screening results, gestational diabetes, preeclampsia, and adverse birth outcomes. Lastly, with the long-term goal of identifying women at high risk of SED during pregnancy and designing effective interventions, the investigators will efficiently evaluate correlates and determinants of SED which have never been studied during pregnancy.