PROJECT SUMMARY/ABSTRACT Obesity is a well-established risk factor for developing cardiometabolic diseases such as diabetes and hypertension. While the impact of obesity on reproductive health is less understood, studies conducted in high- income countries have associated obesity with menstrual and ovulatory dysfunction and subsequent infertility. These findings have significant public health implications for low- and middle-income countries (LMICs) where access to assisted reproduction treatment remains practically nonexistent despite rapidly increasing obesity prevalence. Obesity-related morbidity and mortality are particularly high among Pacific LMICs. However, few studies have assessed the relationship between cardiometabolic and reproductive health in this region. Previous attempts to characterize menstrual irregularity among Pacific Islander women have relied on retrospective self-report of cycle length and variability, which is notoriously subject to recall bias and interlocuter variation. No studies to date have characterized anovulatory cycles among Pacific Islander women. This is likely because the gold-standard for determining ovulation involves daily transvaginal ultrasonography, an invasive and resource-intensive procedure that is impractical for epidemiological studies. My proposal addresses these gaps through two scientific aims and five training aims that leverage an existing cohort of approximately n=150 Samoan women aged 25-39, whose families Dr. Nicola Hawley (sponsor) and colleagues have followed since 2015. These women have participated in health and wellbeing assessments in 2015, 2017/2018, and 2019/2020. During the fourth data collection wave planned for 2022, I will measure adiposity and prospectively assess ovulatory function. In Aim 1, I will examine associations between menstrual irregularity and current adiposity and longitudinal trajectories of change in adiposity among Samoan women. In Aim 2, I will biochemically evaluate the presence or absence of ovulation among regularly menstruating women and explore the association between anovulation and BMI. Findings will provide critical insight on secondary infertility among women with obesity and inform the development of protocols for evaluating female reproductive potential in low-resource settings. Moreover, this project will shed light on the dual burden of cardiometabolic and reproductive risk among Pacific Islander women, who despite having among the highest obesity prevalence globally, are underrepresented in epidemiologic research. My training plan will enable me to develop research, clinical, and professional skills necessary to become a physician-scientist who conducts longitudinal epidemiologic studies to investigate the impact of obesity on maternal and child health outcomes in low-resource settings. My training plan outlines coursework, mentored research, and clinical experiences to enhance my skills in biostatistics, epidemiological study design and impleme...