Sleep health and uterine leiomyomata incidence and growth: a prospective ultrasound study

Poor sleep may negatively impact reproductive outcomes, yet its role in uterine leiomyomata (UL) development has not been studied. We estimated prospectively the association of self-reported sleep health with ultrasound-detected UL incidence and growth in the Study of Environment, Lifestyle, and Fibroids, a prospective cohort of Black individuals aged 23-35 years in Detroit, Michigan. At each of five clinic visits (2010-2020), participants reported sleep duration, frequency of trouble sleeping, and sleep quality, and underwent transvaginal ultrasound to detect incident UL. We used Cox proportional hazards regression models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) and applied inverse probability weights to adjust for time-dependent confounding. Among 1,137 participants, 351 developed UL (10-year cumulative incidence: 30.9%). Short (<6 hours/day, HR=0.30 95% CI: 0.17, 0.55) sleep duration and consistently poorer sleep quality (<4 days/week feeling well-rested, HR=0.78, 95% CI: 0.56, 1.08) were associated with lower UL incidence. Increased frequency of trouble sleeping was positively associated with UL incidence (≥15 days/month, HR=1.96, 95% CI: 0.76, 5.09). Sleep health was not associated with UL growth. In this prospective ultrasound study, sleep measures were inconsistently associated with UL incidence and not associated with UL growth.