Preconception sleep quality moderates the association between preconception hair cortisol levels and mental health in pregnant women

Background: Poor sleep quality may elevate cortisol levels and affect prenatal mental health through altered HPA axis functioning. This study aims to examine whether subjective sleep quality during preconception moderates the association between preconception hair cortisol levels and mental health from preconception to pregnancy trimesters. Methods: Women from a prospective cohort study completed the Pittsburgh Sleep Quality Index (PSQI), the Edinburgh Postnatal Depression Scale (EPDS), and the State-Trait Anxiety Inventory (STAI) questionnaires during preconception (T0) and at each pregnancy trimesters (T1, T2, and T3). We analyzed 266 of these women who conceived and had fully completed measures at preconception for hair cortisol, sleep quality and either EPDS or STAI-state. Changes in EPDS and STAI-state scores were derived (i.e., T1–T0, T2–T0, T3–T0). Johnson-Neyman technique identified PSQI scores with significant moderation of cortisol on mental health. Results: After adjusting for potential covariates, there was a significant positive correlation between preconception hair cortisol levels and depressive symptom at the second trimester (rs (144) = 0.22, p = 0.008), but not the first and third trimesters (all ps > 0.05). The positive association between preconception hair cortisol and change in depressive symptoms between third trimester and preconception was significant only among women with poor preconception sleep quality (PSQI ≥ 7). Limitations: Sleep quality and prenatal mood were derived from self-reported questionnaires, which may be more susceptible to bias. Conclusions: The positive association between preconception hair cortisol and change in prenatal depressive symptoms is significant among women who reported poor sleep quality during preconception. Improving preconception sleep quality can potentially mitigate the association between preconception hair cortisol and depressive symptoms during pregnancy.