Low serum placental lactogen at term is associated with postnatal symptoms of depression and anxiety in women delivering female infants

Background: Placental endocrine insufficiency may increase the risk of depression and anxiety during pregnancy and/or after birth. This study investigated the association between serum human placental lactogen (hPL) and measures of perinatal mental health, accounting for selective serotonin-reuptake inhibitor (SSRI) usage. Method: Caucasian women with singleton, term pregnancies recruited at their pre-surgical appointment prior to an elective caesarean section (ELCS) were studied. Serum hPL levels were measured by ELISA in maternal blood collected at the pre-surgical appointment. Depression and anxiety scores were derived from Edinburgh Postnatal Depression Scale (EPDS) and the trait subscale of the State-Trait Anxiety Inventory (STAI) questionnaires completed at recruitment and three postnatal time points. Data was analysed by unadjusted and adjusted multiple linear regression. Results: In adjusted linear regressions, term maternal serum hPL levels were negatively associated with postnatal EPDS and STAI score ten weeks postnatal for mothers who had girls (B = -.367, p = .022, 95% CI -.679, -.056; and B = -.776, p = .030, 95% CI -1.475, -.077 respectively). Excluding women prescribed SSRIs strengthened the relationship at 10 weeks and uncovered an earlier association between hPL and mood scores within one week of delivery (EPDS B = -.357, p = .041, 95 % CI -.698, -.015; and STAI B = -.737, p = .027, 95 % CI -1.387, -.086). In mothers who had boys, there were no associations between hPL and mood scores at any time point. Conclusion: Low hPL at term associated with postnatal depression and anxiety symptoms exclusively in mothers of girls. Insufficiency in hPL may contribute to maternal mood symptoms.