PROJECT ABSTRACT New HIV infections during pregnancy and breastfeeding represents the last mile in achieving elimination of mother to child transmission (EMTCT) of HIV. However, little focus has been directed towards structured, antenatal care based strategies or interventions to prevent HIV acquisition among pregnant and breastfeeding women without HIV who receive HIV testing in ANC. Pregnant and breastfeeding women in sub-Saharan Africa (SSA) like Malawi face high rates of HIV incidence. Pre-exposure prophylaxis (PrEP) represents an important biomedical intervention in the growing fight for EMTCT. With good adherence, daily oral tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) has been shown to effectively reduce new HIV infections and is considered safe in pregnancy. Despite oral PrEP promise in reducing HIV acquisition, significant implementation challenges exist that result in poor adherence and losses to follow up. New PrEP options in the form of the recently U.S. Food and Drug Administration (FDA) approved long-acting Cabotegravir injectable (CAB-LA) offer more effective and discrete options that may help address issues of poor adherence. However, the safety data in pregnancy and breastfeeding remain limited for CAB-LA for PrEP. As women conceive while receiving PrEP for HIV prevention, obtaining pregnancy safety data for emerging PrEP antiretroviral drugs such as CAB-LA is important before widespread roll out of the drug in national PrEP programs. The overall goal of this project is therefore to establish and evaluate surveillance and monitoring systems among pregnant and breastfeeding women exposed to PrEP (oral PrEP and CAB-LA). Investigators will enroll a cohort of women who are judged to be at high risk of HIV acquisition categorized according to use of oral PrEP or injectable PrEP. In Aim 1, the investigators will establish a PrEP pregnancy registry into which all women who begin PrEP during pregnancy or who become pregnant while receiving PrEP will be entered into a PrEP in pregnancy registry and followed up to their pregnancy outcome. In Aim 2 the investigators will establish a prospective safety cohort of pregnant women with PrEP exposure. Women will be followed throughout pregnancy and delivery to obtain their birth outcomes. The mother-infant pairs will be followed up to about 12 months after delivery. For this aim they also evaluate acceptability of injectable PrEP and daily use of daily oral PrEP and will also determine whether rates of adverse pregnancy outcomes (preterm birth, stillbirth, miscarriages) and other clinical outcomes differ according to PrEP use status (CAB-LA vs. oral PrEP). Aim 3 focuses on assessing the growth and neurodevelopmental outcomes among the infants exposed to PrEP during pregnancy. Infants exposed to either oral PrEP or CAB-LA will have nutritional assessments based on World Health Organization (WHO) approved classifications.