The association between time-to-pregnancy and postpartum depressive symptoms in a North American prospective cohort study

Purpose: To prospectively examine the association between time-to-pregnancy (TTP) and postpartum de-pression (PPD) and determine whether perceived stress during early pregnancy mediated this association.Methods: In Pregnancy Study Online, an internet-based preconception cohort study of pregnancy plan-ners, participants completed questionnaires every 8 weeks for up to 12 months or conception, during pregnancy, and at postpartum. A total of 2643 women provided information on sociodemographic factors, reproductive history, and stress (i.e., Perceived Stress Scale [PSS]) during preconception and early preg-nancy (completed at-4-12 weeks' gestation) and on postpartum depressive symptoms (i.e., Edinburgh Postnatal Depression Scale [EPDS]) at-6 months postpartum. We used multivariable modified Poisson regression models to estimate risk ratios and 95% confidence intervals (CIs) for the association between TTP ( < 3, 3-5, 6-11, >= 12 menstrual cycles) and PPD (EPDS score >= 13). Causal mediation analyses assessed the mediating role of early pregnancy PSS scores.Results: 10.6% of women had EPDS scores indicating possible PPD ( >= 13). Compared with women who took less than 3 cycles to conceive, risk ratios for those who took 3-5, 6-11, and greater than or equal to 12 were 1.06 (95% CI: 0.77, 1.45), 1.24 (95% CI: 0.90, 1.70), and 1.31 (95% CI: 0.87, 1.99), respectively. Approximately 30% of the association between infertility (TTP >= 12) and PPD was mediated by early pregnancy PSS.Conclusions: There was a modest positive dose-response association between delayed conception and PPD. Perceived stress in early pregnancy explained a small proportion of this association. However, given the width of the CIs, chance cannot be ruled out as an explanation for the observed association.Published by Elsevier Inc.