Understanding team membership is necessary to inform interventions to improve teamwork. In this study, we examine the team membership of a team managing maternal hemorrhage (MH) events, e.g., events in which the patient experiences excessive blood loss following childbirth. We performed observations and fielded a close-ended survey to understand the care processes and perceived team membership. Our results from the observations showed that the care processes consist of four phases of care, i.e., triage, labor and delivery, postpartum care, and surgical intervention. Our results from the survey showed that clinicians, even those with the same clinical expertise, perceived their team membership differently, suggesting team membership during MH events is fluid. Current strategies from literature to support teamwork in fluid teams may not be feasible during the MH event care processes. Future research is needed to develop and evaluate interventions to support teamwork during MH event management.