Adverse pregnancy outcomes, including gestational hypertension and preeclampsia, affect 10-20% of pregnant women and are major risk factors for future maternal cardiovascular disease (CVD). Though moderate-to- vigorous intensity physical activity (MVPA) during pregnancy can reduce these risks, less than 25% of pregnant women meet MVPA guidelines. Identification of additional modifiable behaviors that could reduce maternal health risks during pregnancy is needed to inform clinical interventions and practice. Remarkably, little is known about the role of sedentary behavior or sleep in adverse pregnancy outcomes that increase future CVD risk. This is a critical research gap because sedentary behavior and sleep are increasingly recognized as CVD risk factors in the general population, independent of MVPA. Unfortunately, existing studies in pregnancy largely focus on MVPA rather than the emerging paradigm that considers the full 24-hour behavioral cycle (i.e., sedentary behavior, sleep, light-intensity physical activity, and MVPA), lack repeated measures, use suboptimal assessment methods, and fail to measure clinically relevant outcomes. Clarifying how sedentary behavior and sleep influence pregnancy outcomes could inform intervention targets and guidelines to improve cardiovascular health during and after pregnancy. The overall goal of the proposed study is to examine the associations of sedentary behavior (Aim 1) and sleep (Aim 2) with hypertensive disorders of pregnancy and other adverse pregnancy outcomes that increase future CVD risk. Novel statistical methods will be used to determine optimal 24-hour behavioral patterns (Aim 3) during pregnancy for cardiovascular health. For this, 500 women in early pregnancy will be recruited to take part in a multi-site (Universities of Iowa and Pittsburgh) cohort study. Women will wear three state-of-the-art devices for seven days in each trimester of pregnancy to assess sedentary behavior (activPAL micro 3), sleep (ActiWatch Spectrum Plus), and physical activity (ActiGraph GT3X). Hypertensive disorders of pregnancy and other adverse outcomes will be obtained through medical chart abstraction. We hypothesize that women with a high sedentary behavior pattern, short sleep duration pattern, and poor sleep quality pattern across trimesters will be more likely to have hypertensive disorders of pregnancy (primary), gestational diabetes, preterm birth, small-for-gestational age infants, high blood pressure, and poor glycemic control (secondary). Further, we hypothesize that statistically reallocating time spent in sedentary behavior for physical activity (LPA or MVPA), but not sleep (among adequate or high duration sleepers), will be associated with lower incidence of these adverse outcomes. In direct response to the NHLBI Research Priority 3.CC.04, this project will use advanced methods and models to assess and characterize the 24-hour behavioral cycle during pregnancy to better understand differences in health. This project will inform guidelines on optimal 24-hour behavioral patterns in pregnancy, as well as lay the foundation for future studies testing behavioral interventions in pregnancy to achieve optimal outcomes and improve women?s long-term cardiovascular health.

Public Health Relevance

Moderate to vigorous intensity physical activity is known to reduce the risk of hypertensive disorders of pregnancy and other adverse pregnancy outcomes that increase future maternal cardiovascular disease risk, yet less than 25% of pregnant women meet public health activity guidelines. More than 95% of the 24-hour day is spent in sedentary behavior, sleep, or light-intensity activity; however, the impacts of these lower intensity activities on adverse pregnancy outcomes are unknown. This multi-site observational cohort study will leverage state-of-the-art, 24-hour behavior assessment in each trimester of pregnancy and examine associations with adverse pregnancy outcomes to inform guidelines and future interventions designed to improve women?s pregnancy and long-term cardiovascular health.

National Institute of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Research Project (R01)
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Cancer, Heart, and Sleep Epidemiology B Study Section (CHSB)
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Ludlam, Shari
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University of Iowa
Schools of Arts and Sciences
Iowa City
United States
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