Reproductive
Subjective sleep health and menstrual cycle characteristics in a North American prospective cohort study Chad M. Coleman* Chad M. Coleman Traci N. Bethea Tanran R. Wang Andrea S. Kuriyama Julia C. Bond Wendy Kuohung Yael I. Nillni Lauren A. Wise Amelia K. Wesselink
Introduction: Menstrual cycle disturbances affect up to 30% of reproductive-aged individuals. Few studies have examined the effect of sleep on menstrual cycle characteristics.
Methods: We estimated the associations of subjective sleep duration and quality with menstrual cycle characteristics in Pregnancy Study Online, a web-based North American preconception cohort study (2013-2023). Eligible participants were aged 21-45 years, assigned female sex at birth, and not using contraception or fertility treatment. On the baseline questionnaire, participants reported sleep duration (hours/day) in the past month. Beginning in October 2020, we assessed sleep quality in the past month via the Pittsburgh Sleep Quality Index (PSQI). On a follow-up questionnaire completed 8 weeks after baseline, participants reported menstrual cycle characteristics, including regularity, cycle length, bleed length, flow volume, intermenstrual bleeding, and menstrual pain. We used log-binomial regression models to estimate prevalence ratios (PRs) and 95% CIs adjusting for socio-demographic, behavioral, and reproductive factors.
Results: Short (<6 hours/day) and long (≥9 hours/day) sleep durations were associated with increased prevalence of prolonged bleed length (≥7 days; PRs vs. 7-<9 hours/day=2.10 [CI: 0.99-4.45] and 1.64 [CI: 0.89-2.99], respectively) and intermenstrual bleeding (PRs=1.59 [CI: 1.01-2.51] and 1.50 [CI: 1.05-2.14], respectively). Relative to good sleep quality (PSQI ≤5), poor sleep quality (PSQI >5) was associated with prolonged bleed length (PR=1.44 [CI: 0.93-2.23]), intermenstrual bleeding (PR=1.13 [CI: 0.88-1.45]), and severe menstrual pain (PR=1.29 [CI: 1.09-1.53]). Sleep duration and quality were not appreciably associated with other menstrual characteristics.
Conclusions: Sleep duration and quality were associated with menstrual cycle disturbances in this cohort. As sleep is a modifiable health behavior, this work may inform interventions to improve gynecologic health.