Patterns of sleep duration, quality, and midpoint across pregnancy in a longitudinal cohort study

Abstract Background Sleep health is a critical component of maternal well-being, and poor sleep during pregnancy is associated with adverse maternal-fetal and cardiometabolic outcomes. Although sleep across pregnancy has been examined in several longitudinal studies, fewer studies have included frequent repeated assessments in racially and ethnically diverse populations with a high representation of lower socioeconomic status. We aimed to characterize longitudinal patterns of sleep duration, sleep quality, and sleep midpoint across pregnancy; identify groups with similar sleep profiles; and examine maternal and pregnancy characteristics associated with sleep health. Methods This secondary analysis included individuals enrolled in the Human Placenta and Phthalates Study in Norfolk, Virginia and Galveston, Texas (2016–2020). Self-reported sleep duration and quality were collected at up to eight visits (13–36 gestational weeks). Sleep midpoint was calculated from reported bedtime and wake time. Generalized estimating equations evaluated associations between participant characteristics and repeated sleep measures. Group-based trajectory modeling identified joint trajectories of reported bed and wake times for perceived overnight sleep duration and perceived sleep quality; sleep midpoint was excluded because models incorporating it did not converge. Results Among 303 individuals, 43% were non-Hispanic Black (NHB), 39% non-Hispanic White (NHW), 16% Hispanic/Latina, and 72% had government-assisted health insurance. Across pregnancy, the proportion of individuals reporting short sleep increased modestly, perceived sleep quality worsened, and sleep midpoint remained relatively stable, with no differences in overall patterns by race and ethnicity. On average, NHB individuals were 8% more likely to report short sleep (< 7 h), and Hispanic/Latina individuals reported better sleep quality than NHW individuals. Higher BMI, lower educational attainment, parity, and government insurance were associated with worse sleep across domains. Three joint trajectory groups were identified: “Worst Sleepers” (short duration/poor quality; 60.7%), “Restless Sleepers” (7–9 h/lower quality; 25.4%), and “Best Sleepers” (adequate duration/high quality; 13.9%); 64% of NHB and 53% of nulliparous individuals were classified as “Worst Sleepers.” Conclusions Adverse sleep patterns were common across pregnancy. The findings support evaluating both sleep quantity and perceived quality during prenatal care and investigating modifiable clinical, social, and environmental contributors to persistent sleep difficulties, particularly among groups disproportionately represented in unfavorable sleep profiles.