Exploring associations between postpartum depression and oxytocin levels in cerebrospinal fluid, plasma and saliva

Background: Postpartum depression (PPD) is a serious mental health concern affecting approximately 17.22 % of new mothers worldwide. In addition to its obstetric effects, oxytocin (OXT) has also been considered to play a role in PPD. However, most previous studies exploring associations between PPD and OXT levels focus on easier accessible compartments such as blood or saliva. Study aim: To explore the possible association between PPD and OXT levels, and to assess the interaction between peripheral secretion and central release of OXT. Methods: In this study, we prospectively measured OXT concentrations in cerebrospinal fluid (CSF), plasma and saliva of 94 women with elective cesarean section by enzyme-linked immunosorbent assay (ELISA) kits. The participants were divided into the PPD group if the score of Edinburgh Postpartum Depression Scale (EPDS) >= 10 at 3 months postpartum, otherwise into the non-PPD (nPPD) group. Results: The incidence of PPD was 30.85 %. OXT concentrations in CSF (r =-0.518, p < 0.001), plasma (r =-0.240, p = 0.020) and saliva (r =-0.263, p = 0.010) were negatively correlated with EPDS score, and were valuable for the prediction of PPD, with AUC and 95%CI of 0.890 (0.809-0.945), 0.683 (0.579-0.775) and 0.699 (0.596-0.790), respectively. Moreover, OXT concentrations in plasma (r = 0.407, p < 0.001) and saliva (r = 0.624, p < 0.001) were positively correlated with CSF OXT concentrations. Limitations: Only full-term pregnant women undergoing elective cesarean section were included in this study, which may affect study generalizability. Conclusions: The central and peripheral release of OXT is coordinated, and OXT level measured prenatally in CSF, plasma, or saliva is valuable for the prediction of PPD.