Trajectories of maternal depressive symptoms from pregnancy to 11 years postpartum: Findings from Avon Longitudinal Study of Parents and Children (ALSPAC) cohort.

Background: Maternal depressive symptoms are common in pregnancy and may extend to the perinatal period and beyond for some women. To date, few longitudinal studies have investigated maternal depressive symptoms from pregnancy to eleven years postpartum. Drawing data from a large population-based study cohort the aims of this study were to 1) identify distinct groups of mothers defined by their trajectories of depressive symptoms spanning from pregnancy to eleven years following the birth of the child, and 2) to identify psychosocial risk factors during pregnancy and in the first few postnatal years that are associated with these trajectories.

Methods: Data were analyzed from 14,170 mothers who participated in Avon Longitudinal Study of Parents and Children (ALSPAC). The Edinburgh Postnatal Depression Scale (EPDS) was used to capture maternal depressive symptoms across 10 time points including two prenatal (18 and 32 weeks), and eight postnatal (2, 8, 21, 33, 61, 73, 97 and 134 months) time points. The latent growth model was created to describe the course of maternal depressive symptoms across the preceding time points followed by a latent growth mixture modelling (LGMM) to identify distinct trajectories of depressive symptoms over time within the overall sample. The predictors of maternal depressive symptoms trajectories were categorized into sociodemographic, child, and psychosocial factors. The multinomial regression analyses were conducted to explore associations between the risk factors and depressive symptoms trajectories.

Results: LGMM identified four distinct trajectories of maternal depressive symptoms over time: minimal symptoms, increasing symptoms, persistent symptoms, and decreasing symptoms. Predictors of all patterns of depression - persistent, increasing and decreasing symptoms include smoking during pregnancy, and partner conflict. The strongest predictors of the persistent symptom trajectory included maternal history of depression and inadequate social support.

Limitations: The use of self-reported maternal mental health symptoms and under representation of ethnic minorities are our study's limitations.

Conclusions: The study findings highlight the importance of early identification and treatment for mothers experiencing depressive symptoms from pregnancy to the perinatal period and beyond.