Our current study examines the effect of gestational arsenic exposure on the maternal heart postpartum. We found that exposure to arsenite increased postpartum heart size, altered cardiomyocyte Ca2+-handling and contraction, and expression of key contractile proteins, including α-Actin and cardiac myosin binding protein C (cMyBP-C). Together, t hese findings suggest that gestational arsenic exposure impacts the postpartum maternal heart, inducing long-term cardiovascular changes, and highlight the need for more research on the impact environmental exposures on maternal heart health and adverse pregnancy events.