In the United States, maternal health inequities disproportionately affect Global Majority (e.g., Asian, Black, and Hispanic) populations. Despite a substantial body of research underscoring the influence of racism on these inequities, little research has examined how experiences of gendered racial microaggressions during pregnancy and birth impact racially and ethnically diverse Global Majority pregnant and birthing people in obstetric hospital settings. We evaluated the psychometric properties of an adapted version of Lewis & Neville’s Gendered Racial Microaggressions Scale, using data collected from 417 Global Majority birthing people. Findings from our study indicate that our adapted GRMS is a valid tool for assessing the experiences of gendered racial microaggressions in hospital-based obstetric care settings among Global Majority pregnant and birthing people whose preferred languages are English or Spanish. Item Response Theory (IRT) analysis demonstrated high construct validity of the adapted GRMS scale (Root Mean Square Error of Approximation = 0.1089 (95% CI 0.0921, 0.1263), Comparative Fit Index = 0.977, Standardized Root Mean Square Residual = 0.075, log-likelihood c2 = -85.6, df = 8). IRT analyses demonstrated that the unidimensional model was preferred to the bi-dimensional model as it was more interpretable, had lower AIC and BIC, and all items had large discrimination parameters onto a single factor (all discrimination parameters > 3.0). Given that we found similar response profiles among Black and Hispanic respondents, our Differential Item Functioning analyses support validity among Black, Hispanic, and Spanish-speaking birthing people. Inter-item correlations demonstrated adequate scale reliability, α = 0.97, and empirical reliability = 0.67. Pearsons correlations was used to assess the criterion validity of our adapted scale. Our scale’s total score was significantly and positively related to postpartum depression and anxiety. Researchers and practitioners should seek to address instances of gendered racial microaggressions in obstetric settings, as they are manifestations of systemic and interpersonal racism, and impact postpartum health.