PROJECT SUMMARY/ABSTRACT DESCRIPTION: State the application's broad, long-term objectives and specific aims, making reference to the health relatedness of the project (i.e., relevance to the mission of the agency). Describe the research design and methods for achieving the stated goals. Be sure that the project summary reflects the key focus of the proposed project so that the application can be appropriately categorized. Do not include proprietary/confidential information or trade secrets. DO NOT EXCEED THE SPACE PROVIDED. This R61/R33 application proposes to adapt and test an evidence-based behavioral intervention to decrease polysubstance use (i.e., alcohol and tobacco/cannabis) during pregnancy and lactation and prevent adverse clinical outcomes, including fetal alcohol spectrum disorder (FASD) in South Africa (SA). SA has a long history of social and health disparities, resulting in the world's highest rate of FASD (111.1 per 1,000), where lifelong negative cognitive and physical effects result from prenatal alcohol exposure. FASD is completely preventable if women do not drink during pregnancy. Prenatal alcohol use frequently co-occurs with other substance use, especially tobacco and cannabis. The adverse effect on birth outcomes by alcohol and tobacco use together is worse than either substance alone. Recent evidence from animal models shows that prenatal exposure to both cannabinoids and alcohol potentiate the likelihood of alcohol-induced birth defects. Data from Cape Metropole, SA, showed that all women who reported prenatal alcohol use also tested positive for tobacco use, with 25% also reporting cannabis use. Alcohol use while breastfeeding also occurs at a relatively high rate in SA. Despite tremendous health benefits from breastfeeding, maternal alcohol use while breastfeeding significantly compromises infant development. Contingency management (CM) has been efficacious in reducing prenatal cocaine, alcohol, and tobacco use in the United States (U.S.). The Women's Health CoOp (WHC) is an evidence-based brief intervention addressing women-focused syndemic issues and resulting disparities associated with substance and alcohol use. These evidence-based interventions need to be combined and adapted for addressing maternal polysubstance use and associated health and behavioral issues during pregnancy and lactation in SA. The Specific Aims are as follows: (1) R61 Aim 1— Conduct formative qualitative research with women who are pregnant or breastfeeding with a recent history of polysubstance use, clinic and community stakeholders, and an established Community Collaborative Board. (2) R61 Aim 2—Test feasibility, acceptability, and appropriateness of the adapted intervention with 48 women (24 pregnant and 24 breastfeeding) in Cape Metropole, SA. (3) R33 Aim 1—Examine the effectiveness of the adapted intervention (i.e., CM and text-based support with WHC educational components) in a 2-group randomized controlled trial with 184 women who are p...