PROJECT SUMMARY Hispanic women are up to 70% more likely to experience infertility (i.e., trying to conceive for ≥12 months without success), compared to non-Hispanic white women in the US (NHWW). Recent studies indicate that women with a history of infertility may be at greater risk of cancer, cardiometabolic diseases, and mortality later in life and that risk may vary among specific infertility diagnoses (e.g., endometriosis, tubal factor infertility, and polycystic ovary syndrome). Prior research has shown that the severity, incidence, and risk factor profiles for cancer, cardiometabolic diseases, and mortality differs between Hispanic women and NHWW. However, there has been a paucity of research on infertility and long-term health outcomes among Hispanic women, despite Hispanics being the largest minority group in the US with two-thirds having Mexican heritage. Our proposal will utilize the Mexican Teachers´ Cohort (MTC), a prospective cohort study of 115,306 women from 12 geographically diverse states in Mexico who were a median age of 44 (range 20-84) when the cohort began in 2006-2008. MTC has collected data for 18 years. The MTC will harnesses detailed data on reproductive health, including information on specific infertility diagnoses (e.g., PCOS, ovulatory, tubal, endometriosis, male factor), infertility treatments, and pregnancy history. The cohort has validated information on disease endpoints including breast cancer, ovarian cancer (recently funded by NCI), diabetes, and mortality through linked electronic health records and a national mortality registry through 2019. In the planned proposal, we will leverage our successful methodology to validate incident breast cancer, diabetes, and mortality cases (2019-2024), and identify and confirm endometrial cancer, ischemic heart disease and stroke cases (2006-2024). Specifically, our proposal will: Aim 1. Determine the risk of cancer for women with a history of infertility compared to parous women without infertility; Aim 2. Determine the risk of cardiometabolic diseases for women with a history of infertility compared to parous women without infertility; Aim 3. Determine the risk of premature mortality for women with a history of infertility compared to parous women without infertility. The chronic disease risk for Hispanic women with infertility is not known despite their high infertility disease burden and unique chronic disease profile. This gap in knowledge precludes them from benefitting from early screening and interventions which may ultimately reduce morbidity and mortality. This proposal, utilizing a large, well-characterized resource of women with Mexican heritage, is the first step towards filling a substantial gap in understanding risk of long-term health outcomes among Hispanic women, the largest minority group in the US.