Salivary cortisol, progesterone, and estradiol levels across the perinatal period and associations with depressive symptoms.

Depression during pregnancy and postpartum has impacts on both the birthing parent and offspring. This period is characterized by changes in which stress (e.g., cortisol) and reproductive hormone (e.g., progesterone and estradiol) levels gradually increase across pregnancy and decrease rapidly postpartum, but there are mixed associations of cortisol, progesterone, and estradiol levels with depressive symptoms. Prior studies typically have focused on single hormones across time or multiple hormones at a single time point. The present study aimed to expand the literature by examining patterns of cortisol, progesterone, and estradiol assayed from saliva collected at waking in 77 women in mid-pregnancy, late pregnancy, and 8 weeks postpartum. We tested changes in overall hormone levels across time using linear mixed-effects models and cross-sectional and longitudinal associations with depressive symptoms using correlations and regressions. Levels of progesterone and estradiol increased from mid- to late pregnancy, then decreased from late pregnancy to 8 weeks postpartum. Cortisol did not change from mid- to late pregnancy but decreased postpartum. Lower mid-pregnancy cortisol was associated with higher mid- and late pregnancy depressive symptoms, with similar magnitudes accounting for covariates. Lower mid-pregnancy estradiol was associated with higher late pregnancy depressive symptoms, although this association no longer reached statistical significance separately accounting for gestational age, parity, or body mass index in regression models. Pregnancy hormones were not associated with postpartum depressive symptoms. Although hormone levels were prospectively associated with depressive symptoms in pregnancy, associations between estradiol and depressive symptoms may partly reflect other health- or pregnancy-related factors.