The association between sleep trajectories throughout pregnancy and postpartum pain in individuals with overweight or obesity: a prospective cohort study.

Background: Pain after childbirth affects maternal and infant outcomes. Although sleep influences pain in general adult populations, research on this during the perinatal period is limited. This study examines the association between sleep quality and duration changes from mid to late pregnancy and pain during postpartum hospitalization. Methods: This secondary data analysis included 118 pregnant individuals (12-20 weeks gestation at enrollment) with a pre-pregnancy BMI ≥ 25 kg/m². The Pittsburgh Sleep Quality Index estimated sleep quality and duration at six prenatal visits. Group-based trajectory models identified distinct sleep patterns. Pain was assessed every 8 hours during the three-day postpartum hospitalization using a 0-10 numeric rating scale and was then calculated as the pain Area Under the Curve (AUC). Multivariable-adjusted linear regression analyzed the relationship between sleep trajectories and postpartum pain. Results: Two trajectories for sleep quality and two for sleep duration were identified. The "Consistently poor" group showed increasing PSQI scores from 9 to 11, while the "Late worsening" group's scores increased from 4 to 6. The "Late decreasing" duration group consistently slept 6-7 hours, while the "Consistently short" group maintained 5-6 hours nightly. No significant associations were found between sleep quality (expβ = 0.77, 95% CI: 0.51 to 1.17, p = 0.22) or duration (expβ = 0.75, 95% CI: 0.46 to 1.21, p = 0.24) and postpartum pain. Conclusions: Sleep quality and duration changes during pregnancy were not associated with postpartum pain in this cohort. Future research should explore sleep's impact on pain later in the postpartum period when chronic pain may develop.