Background: Gonadal steroids interact with immune function and mood regulation: their levels during pregnancy, and their subsequent drop during the postpartum period, have been hypothesized to contribute to prepartum depressive symptoms. The objective was to estimate if a previously reported interaction between C-reactive protein (CRP) and peripartum depressive symptoms is at least partially mediated or modified by levels of gonadal steroids. The study group comprised 29 women at high-risk for developing postpartum depression. Methods: We conducted a preliminary longitudinal study with 29 women who were at high-risk of developing depressive symptoms during pregnancy and after delivery. Typical and atypical depression scores were measured at 35-38 weeks' gestation, 1-5 days postpartum, and 5-6 weeks postpartum. Estradiol, progesterone, testosterone, CRP, and interleukin-6 were measured at each time point. Results: Prepartum CRP and atypical depression scores remained significantly correlated after adjusting for gonadal steroid levels.
Conclusions:In future larger studies that address the role of potential inflammatory markers in prepartum depression, adjustment for gonadal steroids might not be necessary. However, future studies investigating interactions between prolactin, HPA axis and gonadal steroids and molecular and cellular mediators of inflammation, and their downstream effects could lead to new understanding and therapeutic targeting of peripartum depression.