BACKGROUND:Postpartum depression and anxiety are prevalent in the first year after giving birth and can have problematic health outcomes for the mother and infant, although further research is required about the factors that contribute to their development. This study explored the trajectory of depressive and anxiety symptoms across the first postpartum year and their associations with body attitudes, body mass index, and weight retention. METHODS:Participants were 467 women recruited during pregnancy via online forums, in parenting magazines, and at baby and children's markets, or from a large tertiary Australian hospital. Participants reported retrospectively on the prepregnancy period and provided data in early pregnancy (Baseline; M = 17.1 weeks pregnant), at 3 months postpartum (T1; M = 13.1 weeks after birth), 6 months postpartum (T2; M = 26.6 weeks after birth), and 12 months postpartum (T3; M = 52.8 weeks after birth). RESULTS:Latent growth curve modelling revealed that, from T1 to T3, depressive symptoms significantly decreased, whereas anxiety symptoms did not change significantly. Demographic factors, weight retention, body mass index, and body attitudes at T1 did not significantly predict the course of depression and anxiety over time; however, greater postpartum weight retention and negative body attitudes at T1 predicted a more severe experience of both depression and anxiety at T3. CONCLUSIONS:These findings emphasize the need to assess and monitor the risk factors that can have an adverse impact on postpartum women's psychological health. This finding is particularly important for women deemed to be at risk of problematic body image or weight issues so that health professionals can intervene, and better ensure the health of new mothers in the longer term.