Background: Postpartum depression (PPD) affects about 10-20% of birthing parents and low-income birthing parents are at high risk. It is important to address PPD due to the associated negative outcomes for both birthing parent and child. The Manitoba Healthy Baby (HB) program has two components: Prenatal Benefit (HBPB) and Community Support Programs (HBCSP) aiming to promote perinatal health. While there is evidence indicating that the HB program improves birth and perinatal outcomes, the impact on the birthing parents’ mental health is yet to be examined.

Objective: This study aimed to estimate the effect of participation in the two components of the HB program on the incidence of PPD among low-income birthing parents in Manitoba.

Methods: Using the de-identified, linkable routinely collected data in the Population Research Data Repository housed at the Manitoba Centre for Health Policy (MCHP), all low-income birthing parents who had singleton, vaginal, full-term, live birth of their first child in Manitoba between April 1, 2004, to March 31, 2019, were included (n = 3,561). Generalized Linear Models with Inverse Probability Treatment Weights were used to assess the relative difference in the associated risk of having a PPD diagnosis between exposure groups. Sensitivity to unmeasured confounding was estimated using E-value.

Discussion: Both receipt of the HBPB and prenatal attendance in the HBCSP alone were associated with an increased likelihood of PPD. However, the combination of the two components did not yield statistically significant results, and the association of HBCSP attendance with PPD was only found for rural areas. Although findings may be interpreted as the program causing harm, the more likely explanation is the higher risk profile of those participating in the program and/or the program’s effectiveness in connecting birthing parents to professional help. This study highlights the importance of connecting birthing parents with their primary care provider as it can determine receipt of PPD diagnosis and care. Efforts should be increased to improve the HB program’s reach toward birthing parents who may be at risk for depression to be able to address PPD among this population as well as its associated negative outcomes.