Sleep disturbances are common in the general population, and women are a population at particular risk. Recent studies indicate a link between short sleep duration and sleep disturbances with adverse health risks. Evidence from physiological and epidemiological studies demonstrate an association between short sleep duration and an increased risk of obesity, diabetes, hypertension, and mortality. In addition, specific sleep disorders, in particular sleep disordered breathing have been linked with cardiovascular and metabolic disorders. Despite the emerging evidence of the importance of sleep for health and data that sleep disturbances are common among pregnant women, there is a paucity of research on the potentially important link between sleep and maternal/ fetal outcomes, particularly metabolic and cardiovascular complications of pregnancy. Specifically, there is limited data on how insufficient sleep and sleep disorders may contribute to the development of gestational diabetes, gestational hypertension, and preeclampsia. We have identified a unique and timely opportunity to leverage the resources of the recently established Nulliparous Research Network of 10,000 pregnant women to address the relationship between sleep abnormalities (short sleep duration, poor sleep quality and common sleep disorders) and pregnancy outcomes. The overall hypothesis to be tested is that sleep disturbances are associated with an increase risk for cardiometabolic disorders during pregnancy. Specifically this application proposes to evaluate self-reported and objective sleep/wake characteristics in a large cohort of pregnant women from whom detailed cardiovascular and metabolic pregnancy outcomes will be measured from the first trimester to delivery. The specific aims are: 1) To systematically characterize sleep patterns using survey and actigraphy in a large cohort of pregnant women; 2) To determine the relationships between abnormal sleep patterns (sleep quality and sleep disorders) and cardiovascular and metabolic disorders of pregnancy (gestational hypertension, preeclampsia, gestational diabetes); 3) To determine concordance between self-reported measures of sleep and objectively derived sleep measures (using actigraphy) in a pregnant population. This application will provide the first large scale longitudinal assessment of sleep in a pregnant population and determine the relationship between sleep characteristics and disorders with pregnancy outcomes. The results of this study have the potential to inform and change clinical care to improve pregnancy outcomes.