The goal of this clinical trial is to find better ways to care for pregnant and postpartum adolescent girls and young women (AGYW) aged 15-24 years with HIV in Tanzania, and to prevent them from passing HIV to their babies. The main questions it aims to answer are: * How often do young pregnant women with HIV go to their health appointments and stay on their treatment up to two years after giving birth? * How many babies born to young women with HIV stay HIV-free for two years? * How soon do young women with HIV get pregnant again after giving birth, and what factors affect this? * What are the best ways to help young women with HIV stay in care and stay healthy during and after pregnancy? * What social and structural factors affect whether young pregnant women with HIV go to their health appointments and stay on their treatment? * How can we work with young women with HIV to create and test a package of interventions to improve their healthcare during and after pregnancy? * Can this package of interventions help young women with HIV stay in care and remain healthy during and after pregnancy? Participants will: * Have their health data analyzed via health service records of all women who received HIV prevention services between 2018 and 2020, and were followed until 2023, across 559 health facilities in Tanzania. * Participate in qualitative interviews to share their experiences and challenges with staying in care. * Help to co-create a package of interventions to improve care. * Take part in a cluster-randomized trial to test these interventions. Researchers will compare the outcomes of the intervention package to see if they improve care engagement, retention, and health outcomes for AGYW with HIV during and after pregnancy.