Association between serum 25-hydroxyvitamin D levels measured 24hours after delivery and postpartum depression

ObjectiveTo assess the possible relationship between serum levels of 25[OH]D (25-hydroxyvitamin D) collected 24hours after delivery and postpartum depression in a Chinese cohort sample. DesignCohort study. SettingOne city hospital in Beijing, China. PopulationWomen delivering a full-term, singleton, live-born infant at one city hospital in Beijing between August 2013 and November 2013. MethodsWomen were enrolled immediately postpartum. A blood sample was obtained 24-48hours after childbirth to test serum levels of 25[OH]D. Participation consisted of a visit to an obstetric unit 3months after delivery. Main outcome measureAt 3months' postpartum, women were screened for depression using the Edinburgh Postnatal Depression Scale (EPDS). The primary outcome measure was a prespecified EPDS score of 12. ResultsDuring the study period, 323 women were admitted. In all, 248 agreed to enrol and 213 completed 3months' follow-up (21 were lost to follow-up and 14 withdrew). Of the 213 women who were included, 26 (12.2%) were considered to meet criteria for postpartum depression. Serum 25[OH]D levels in women with no postpartum depression were significantly higher than those in women with postpartum depression (P<0.0001). Based on the receiver operating characteristic curve, the optimal cutoff value for serum 25[OH]D level as an indicator for screening for postpartum depression was estimated to be 10.2ng/ml, with an area under the curve of 0.801 (95%CI 0.704-0.896). In multivariate analysis, there was an increased risk of postpartum depression associated with 25[OH]D levels 10.2ng/ml (OR 7.17, 95%CI 3.81-12.94; P<0.0001) after adjusting for possible confounders. ConclusionOur study demonstrated that lower serum 25[OH]D levels were associated with postpartum depression. This association was independent of other possible variables.