<p>Postpartum depression and parenting both play a role in shaping children’s future behavior. However, there is limited understanding of the interaction and the evolving relationship between depressive symptoms and parenting practices. This study aimed to investigate the bidirectional associations between maternal depressive symptomatology and parenting (maternal self-efficacy, maternal warmth, and maternal hostile-reactive behaviors) in the postpartum period and to assess the moderating effect of breastfeeding and partner support on these associations. Latent growth curve and multigroup analyses were estimated in a sample of 1551 mothers of the 3D pregnancy cohort. Maternal depressive symptomatology and parenting practices were concurrently associated. Bidirectional associations were found between maternal depressive symptomatology and maternal self-efficacy, but not for warmth or hostile-reactive behaviors. Mothers with high perceived partner support showed a significant association between increased maternal warmth and lower depressive symptoms at 24 months. In contrast, mothers with lower perceived partner support demonstrated stronger associations between early hostile-reactive parenting and later depressive symptoms, as well as a greater impact of declining self-efficacy on maternal depressive symptoms. Breastfeeding showed limited moderating effects, with no significant buffering impact on the associations between depressive symptoms and parenting practices. These findings highlight the protective role of partner support in mitigating the adverse effects of depressive symptoms on parenting and vice versa, emphasizing the need for interventions that strengthen maternal self-efficacy and partner involvement to promote maternal mental health.</p>