AbstractBackgroundPerinatal quality improvement lacks valid tools to measure adverse hospital experiences disproportionately impacting Black mothers and birthing people. Measuring and mitigating harm requires using a framework that centers the lived experiences of Black birthing people in evaluating inequitable care, namely, obstetric racism. We sought to develop a valid patient‐reported experience measure (PREM) of Obstetric Racism© in hospital‐based intrapartum care designed for, by, and with Black women as patient, community, and content experts.MethodsPROMIS© instrument development standards adapted with cultural rigor methodology. Phase 1 included item pool generation, modified Delphi method, and cognitive interviews. Phase 2 evaluated the item pool using factor analysis and item response theory.ResultsItems were identified or written to cover 7 previously identified theoretical domains. 806 Black mothers and birthing people completed the pilot test. Factor analysis concluded a 3 factor structure with good fit indices (CFI = 0.931‐0.977, RMSEA = 0.087‐0.10, R2 > .3, residual correlation < 0.15). All items in each factor fit the IRT model and were able to be calibrated. Factor 1, “Humanity,” had 31 items measuring experiences of safety and accountability, autonomy, communication, and empathy. A 12‐item short form was created to ease respondent burden. Factor 2, “Racism,” had 12 items measuring experiences of neglect and mistreatment. Factor 3, “Kinship,” had 7 items measuring hospital denial and disruption of relationships between Black mothers and their child or support system.ConclusionsThe PREM‐OB Scale™ suite is a valid tool to characterize and quantify obstetric racism for use in perinatal improvement initiatives.