Pacific Islanders bear a disproportionate burden of obesity compared to other racial/ethnic minorities and the United States (US) population. Pacific Islanders residing in the US also have high maternal and infant health disparities with disproportionally high rates of preterm birth (\<37 weeks) and low birthweight infants (\<2,500 grams). They are also more likely to experience preeclampsia, primary cesarean birth, excessive gestational weight gain, gestational diabetes mellitus, and low exclusive breastfeeding rates compared to other racial/ethnic minorities and the US population in general. These unique health circumstances increase medical complications and are associated with impaired glucose intolerance, delivery complications, and higher incidence of obesity and metabolic disease risk later in life for infants. Early and consistent supportive care throughout the pregnancy continuum is strongly associated with positive birth outcomes that can mitigate childhood obesity. However, Pacific Islanders are less likely to receive adequate prenatal care compared to other racial and/or ethnic minorities. Our preliminary studies using Arkansas birth records (n=2,488; 2019) have shown that Marshallese experience exceptionally poor perinatal outcomes, even compared to other US Pacific Islanders. Specifically, 15% of Marshallese women received no prenatal care (compared to 1.6% women nationally); more than 50% do not attend the recommended number of prenatal care visits; 19% of Marshallese infants were born preterm (compared to 9.6% nationally); and 15% of Marshallese infants were low birthweight (compared to 8.3% nationally). These poor health outcomes are highly associated with childhood obesity risk through increased odds of rapid infant weight gain and sub-optimal infant feeding practices. Thus, our foundational work demonstrates an urgent need for culturally adapted interventions to engage the Marshallese community in Arkansas in prenatal care that optimize birth outcomes that can mitigate childhood obesity. CenteringPregnancy, an evidenced-based group prenatal care model, challenges the standard model of one- on-one prenatal counseling and has demonstrated effectiveness in other populations in lowering the risk of preterm birth, low birthweight infants, and increasing exclusive breastfeeding initiation compared to women receiving individualized care. Our prior work has demonstrated how challenging delivering group care is to the Marshallese community because of transportation barriers. Mobile health clinics are transforming the US healthcare system by delivering services directly to communities of need. However, mobile health clinics have not yet been implemented with group prenatal programs like CenteringPregnancy in the US. The proposed study will determine the preliminary effectiveness of an innovative Mobile CenteringPregnancy program for Marshallese women while also evaluating implementation determinants and outcomes to inform sustainable scaling of the program.