Background: During pregnancy, short sleep duration is associated with obesity, risk of gestational diabetes (GDM), and adverse mental health outcomes. Chronotype reflects an individual's preference for activity and sleep-wake cycle during a 24 h period. Evening chronotypes have been associated with poorer mental health and unhealthy lifestyle habits. We evaluated the associations between chronotype, sleep, and mental health in women with GDM, during the perinatal period.

Methods: We included 214 women with GDM followed in 2021-2022 from the third trimester of pregnancy up to 6-8 weeks postpartum. We assessed sleep quality, the chronotype (Morning-Eveningness Questionnaire), depressive symptoms, intuitive eating behaviors, and well-being. We adjusted for potential confounders.

Results: In pregnancy, reduced sleep duration, sleep efficiency, and subjective sleep quality were associated with higher depressive symptoms or lower well-being (all p ≤ 0.03). Later bedtime was linked to eating as a means of coping with emotional distress and a lower awareness of internal hunger and satiety cues (both p ≤ 0.02). An earlier chronotype was associated with improved well-being (p = 0.002). At 6-8 weeks postpartum, reduced subjective sleep quality, sleep duration, and later bedtime was associated with higher depressive symptoms, while an earlier chronotype was associated with reduced depressive symptoms (all p ≤ 0.02). Longitudinal analyses revealed that later bedtime during pregnancy predicted more depressive symptoms in the early postpartum (p = 0.04).

Limitations: Casual pathways cannot be determined in an observational study. This study lacks objective sleep measurements.

Conclusion: Our results highlight the associations between sleep patterns and chronotype with mental health and eating behavior in women with GDM.