Key Social Norms Take-aways The Momentum intervention successfully shifted social norms related to postpartum family planning (FP) among first-time mothers in Kinshasa. Key social norms outcomes included increased perceived community support and descriptive and injunctive norms supporting contraceptive use. However, normative expectations (beliefs about what others think one ought to do) remained unchanged, suggesting that while community attitudes may shift with targeted engagement, transforming deeper normative expectations requires sustained, long-term interventions.

Objectives To evaluate the effect of the Momentum project on postpartum FP knowledge, attitudes, social norms, personal agency, and behaviors among adolescent and young first-time mothers in Kinshasa, Democratic Republic of the Congo.

Methods Using a quasi-experimental longitudinal design, the study surveyed 1,927 nulliparous women aged 15–24 across three intervention and three comparison health zones in Kinshasa. Data were collected at baseline (2018) and endline (2020). Mixed-effects and treatment effects models were used to estimate changes in 14 FP-related outcomes, including behavioral, normative, and attitudinal indicators.

Intervention Details Momentum was a gender-transformative community-based intervention delivered by nursing students through home visits and group education. The intervention included counseling on FP, maternal and newborn health, nutrition, and gender equity. Group education was adapted from Program M, promoting awareness of gender inequities and reproductive rights. Participants were followed for 16 months, with services targeting both young mothers and their male partners.

Results The intervention significantly improved knowledge of modern contraceptives, decreased belief in FP myths, increased personal agency, and improved partner communication and modern contraceptive use within 12 months postpartum. Full exposure to both home visits and group education was associated with greater improvements in all behavioral outcomes. Notably, perceived community support for FP improved by 15.4 percentage points, and modern contraceptive use increased by 13.3 percentage points in the intervention group compared to the control.

Conclusions Momentum demonstrated that a gender-transformative, community-based approach can enhance postpartum FP outcomes among young mothers. Social norms around community support and descriptive perceptions can be shifted through targeted intervention, though more entrenched normative expectations may require additional focus. Scaling such interventions requires balancing effectiveness with cost considerations and integrating components into existing health education systems for sustainability.