Brown CC, et al. - In this observational study of 15,631,174 births from 2011 to 2016, researchers ascertained if Medicaid expansion was associated with changes in rates of low birth weight and preterm birth outcomes, both overall and by race/ethnicity. State Medicaid expansion was not significantly related to differences in rates of low birth weight or preterm birth outcomes overall, based on data from 2011-2016, although there were significant improvements in relative disparities for black infants compared with white infants in states that expanded Medicaid vs those that did not. Relative disparities for Hispanic infants have not changed.