Perinatal depression among mothers in a South African birth cohort study: Trajectories from pregnancy to 18 months postpartum

•Perinatal depressive symptom trajectories are understudied in sub-Saharan Africa.•A majority of women had mild levels of depressive symptoms.•The group with persistent severe symptoms had the most risk factors.•Depressive symptom trajectories differed by community context. Perinatal depression affects 21–50% of women in South Africa and poses significant health risks to mothers and children. Trajectories of depressive symptoms change over time and have not been well characterized during the perinatal period in low and middle-income countries. Data from women enrolled in a population-based birth cohort study in Paarl, South Africa with at least 3 depression measures from pregnancy through 18 months postpartum (N = 831) were analyzed. Depressive symptoms were measured continuously using the Edinburgh Postnatal Depression Scale (EPDS). Group-based trajectory models were used to estimate trajectories of depressive symptoms during the perinatal period and multinomial multivariable models to identify predictors of trajectory group membership. Five distinct trajectory patterns of depressive symptoms were identified: moderate levels of depressive symptoms during pregnancy but minimal postpartum (3.5%), minimal levels during pregnancy and increasing postpartum (3.7%), unstable levels peaking at 12 months postpartum (6.6%), mild levels with slight decrease postpartum (82.9%), and severe levels during pregnancy and postpartum (3.1%). Membership in the chronic severe symptom group was associated with stressful life events, sexual intimate partner violence and tobacco use. Modeling limitations prevented determining how changes in psychosocial predictors over time may influence depressive symptom trajectories. Mild to severe depressive symptoms during pregnancy/postpartum were common among this South African cohort. Interventions to treat women with severe chronic depressive symptoms with co-occurring psychosocial issues are urgently needed.