To identify prenatal and perinatal factors that predict women at risk of sub-clinical and major postpartum depression among a cohort of low medical risk pregnant women in Canada.
Data from 1,403 women who completed a randomized controlled trial of supplementary support during pregnancy was analyzed to identify risk factors for sub-clinical and major postpartum depression. The Edinburgh Postnatal Depression Scale (EPDS), completed at eight weeks postpartum, was used to classify each woman's depression symptom severity. Demographic, obstetric, behavioral risk, mental health and psychosocial factors were considered. Multiple logistic regression analyses were used to identify risk factors most predictive of sub-clinical and major postpartum depression.
After adjustment for other covariates, variables that increased the risk of sub-clinical postpartum depression included a history of depression (OR = 2.27, CI = 1.42-3.63), anxiety symptoms during pregnancy (OR = 2.12, CI = 1.09-4.11), being born outside Canada (OR = 1.87, CI = 1.17-3.00), and low parenting self-efficacy (OR = 1.65, CI = 1.06-2.55). Variables that increased the risk of major postpartum depression included a history of depression (OR = 2.78, CI = 1.56-4.97), being born outside Canada (OR = 2.97, CI = 1.70-5.17), depressive symptoms during pregnancy (OR = 2.83, CI = 1.29-6.19) and not breastfeeding at eight weeks postpartum (OR = 2.12, CI = 1.21-3.70).
A history of depression and being born outside Canada predicted women who were at an increased risk of sub-clinical and major postpartum depression. The remaining risk factors specific to sub-clinical and major postpartum depression suggest some differences between women vulnerable to sub-clinical compared to major depressive symptoms in the postpartum period, which may have implications for targeted screening and intervention strategies.