Plastics are found in many aspects of modern life due to their physical characteristics and convenience. They are used every day for disposable shipping and packaging materials, cosmetics, cooking and eating utensils, plastic water bottles, hospital supplies, furniture and clothing, and even laboratory research equipment. Global plastic production has increased from an annual production of 1.5 million metric tons in 1950 to 368 million metric tons in 2018. Subsequent environmental pollution with commercial plastics is rapidly becoming an international problem that is affecting human health and the health of our marine ecosystem. The State of Hawai’i is a land mass located in the middle of the Pacific Ocean that is surrounded by ocean currents that wash large amounts of circulating plastic waste upon our beaches. Over time, plastic debris degrades into microplastics which can be inhaled in the air by humans or ingested by marine life in the waters. Alarmingly, pieces of microplastics have recently been isolated in isolated in human tissue, such as the gut and placenta. The isolation of physical pieces of microplastic particles from human placenta was recently reported in the literature, but the effects that the actual plastic compounds play on maternal, fetal, and placental physiology is poorly understood. As the burden of human exposure to microplastics grows, so does the need to elucidate the role that microplastics may play in affecting pregnancy and women’s health. We will use the Hawaii Reproductive Biospecimen Repository’s (HRBR) collection of banked placenta samples from the past 2 decades to explore the quantity and quality of microplastics found in Hawai’i. It is well known that there are higher rates of preeclampsia and other hypertensive disorders in women with Native Hawaiian and Other Pacific Island (NHOPI) and Filipino heritage compared to Caucasian women. We hypothesize that the presence of microplastics in placental tissue will parallel the increase in plastics pollution in our environment and may play a role placental function and the pathophysiology of adverse pregnancy outcomes such as preeclampsia and fetal growth restriction. We aim to characterize and quantify the presence of microplastics in banked placentas from complicated and uncomplicated pregnancies, leveraging the well-characterized biorepository of collected placenta samples from 2006-2013 using Micro-Raman Spectroscopy and other modern methodologies. In addition, a new cohort of fresh placentas from 2022-2023 will be prospectively collected to explore whether (i) MPs can cross the placental barrier into the fetal umbilical cord and umbilical cord blood and (ii) investigate if placental calcification is linked to accumulating MPs and histopathologic changes associated with preeclampsia and fetal growth restriction, including fibrosis, microinfarctions, and chorangiosis.