PROJECT SUMMARY/ABSTRACT There is strong evidence that incorporating male partners into prenatal care for women living with HIV in sub- Saharan Africa improves treatment outcomes, but there is scant understanding about how these interventions impact postpartum contraceptive uptake. Postpartum contraceptive initiation and continued use (uptake) has a profound impact on the health of the mother and her child. More than 50% of pregnancies among women living with HIV in sub-Saharan Africa are unintended; therefore, enhanced postpartum contraceptive uptake would decrease maternal and child morbidity and mortality. This project will supplement the ongoing Homens para Saúde Mais (HoPS+) [Men for Health Plus] trial – 829 of 1080 planned HIV+ couples enrolled as of 12/19/2019 – a cluster randomized controlled trial to improve maternal HIV treatment uptake via couples-based HIV care and enhanced male partner support in Zambézia Province, Mozambique. Couples in the HoPS+ intervention group receive joint – as opposed to individual – HIV-management during the antenatal and postpartum period and six counselling sessions to develop shared decision making, communication, and conflict resolution skills. The intervention facilitates conversations about postpartum contraception uptake. I will assess whether couple-based care increases postpartum modern contraceptive uptake – defined as hormonal, barrier, and spermicidal methods. I will conduct a systematic review to quantify how couples-based interventions influence modern postpartum contraceptive uptake (Aim 1). This will capture heterogeneity across previous studies and contribute to a robust conceptual map of how male-partner involvement influences postpartum contraceptive use within the information, motivation, behavior model. I will then utilize a thematic analysis to qualitatively explore perceptions of, attitudes towards, and experiences with modern contraceptive use among 20-30 couples in the study (Aim 2). I will gain an understanding about local perceptions of, attitudes towards, and experiences with modern contraceptive use from study participants’ answers to four questions I added to the HoPS+ trial in-depth qualitative interviews. Lastly, I will quantitatively assess the impact of HoPS+ on modern postpartum contraceptive uptake during the 12 months from live birth among women living with HIV (Aim 3). I will assess the odds of modern contraceptive uptake with a generalized linear mixed effect model to account for clustering by study site. I will also assess how attendance at each counselling session among intervention group participants impacts modern postpartum contraceptive uptake during the 12 months from live birth. This project will expand the impact of the HoPS+ trial and prepare me for a career as a public health researcher with an active clinical practice who studies how behavioral interventions impact human health.