Humans live longer than ever. Although women live longer than men, they experience poorer age-matched health. Early identification of women at risk for premature aging could lead to tremendous personal, societal, and health care benefits. Therefore, a leading health challenge is to understand the causes of premature aging and use this to promote heathy aging in women. Pregnancy is a multi-systemic stress test, offering a sex-specific opportunity to understand healthy vs premature aging. Placental accelerated villous maturation (AVM), characterized by hypermature terminal villi for gestational age, reflects premature aging of the placenta. We will test the novel hypothesis that AVM is an early adulthood marker of premature aging. We will determine whether AVM predicts premature aging in mid-life across multiple systems (endocrine, neurocognitive, musculoskeletal, reproductive, respiratory, cardiovascular, and renal), and identify genetic and environmental AVM risk factors. We will leverage three globally unique cohorts: the US Magee Obstetric Maternal and Infant study, the UK Avon Longitudinal Study of Parents and Children and the Dutch PEARLS cohort; and establish a global multidisciplinary collaboration linking placental aging to lifespan aging to provide novel insights into mechanisms underlying women’s somatic aging, potentially identifying strategies to enable women to live longer and healthier lives.