A father-inclusive, gender-transformative parenting program to strengthen parenting and partner relationships among couples with young children in Mwanza, Tanzania (Familia Bora): a study protocol for a cluster-randomized controlled trial and mixed-m

BACKGROUND: Parenting interventions in low- and middle-income countries (LMICs) have largely focused on mothers, with limited attention to fathers, family relationship dynamics, and gender norms that influence caregiving. To address this gap, we co-designed Familia Bora, a multicomponent, father-inclusive parenting program for couples with young children. The program integrates gender-transformative content on parenting, couples' relationships, mental health, and gender equality to support both mothers and fathers and in turn promote early childhood development (ECD). This paper describes the protocol for a hybrid type 1 effectiveness-implementation pilot cluster-randomized controlled trial (RCT) evaluating Familia Bora, delivered by community health workers (CHWs) in rural Tanzania. METHODS: Thirty-three villages in Misungwi and Sengerema districts in Mwanza Region, Tanzania were randomly assigned to receive the Familia Bora program or continue standard-of-care services. In each village, 12 couples with a child aged 0-24 months were randomly selected, for a total of 396 enrolled father-mother-child triads. The intervention will be delivered over 17 weekly sessions by trained CHWs in community group sessions with fathers and mothers participating together throughout. The primary outcome is maternal and paternal engagement in stimulation activities with their young child. Secondary outcomes include various measures of caregiving as reported by mothers and fathers, including parenting attitudes, discipline practices, couples' relationship quality, parenting stress, gender attitudes, and ECD. Analyses will follow an intention-to-treat approach using difference-in-differences to compare changes in outcome scores from baseline to endline between the intervention and control groups. A mixed-methods process evaluation will also be conducted alongside the RCT to assess program fidelity, quality, reach, adoption, potential mechanisms of change, and contextual factors influencing implementation. The process evaluation will draw on multiple data sources, including routine quantitative program monitoring tools, session observations, and longitudinal qualitative in-depth interviews with mothers, fathers, CHWs, and group leaders. DISCUSSION: This study will generate robust evidence on the effects of a multicomponent, couples-based parenting intervention intentionally co-designed to engage both mothers and fathers in the Tanzanian cultural context. The evaluation will examine outcomes at a family-systems level, including impacts on mothers, fathers, couples, and young children. Findings will inform refinements to strengthen program delivery and lay the groundwork for a larger-scale effectiveness trial focused on evaluating effectiveness for ECD outcomes. If successful, Familia Bora has the potential to serve as a scalable model that jointly engages both mothers and fathers, supports parenting holistically by addressing couples' relationships, caregiver mental health, and gender equality, while building CHW capacity to deliver complex parenting programs. Overall, this study will advance the design and evaluation of father-inclusive, multicomponent parenting programs and inform policy, practice, and future research in Tanzania and similar low-resource settings. TRIAL REGISTRATION: ClinicalTrials.gov #NCT07025447. Prospectively registered on June 9, 2025.