BACKGROUND Critically ill expectant mothers are regularly transferred from obstetrics units to an intensive care unit (ICU), placing one specialty population in an environment designed for another. OBJECTIVE The purpose of this study is to examine the rates of admission, admitting diagnoses, and mortality of obstetric intensive care patients in the United States and peer nations, and discuss implications to the critical care nurse. METHODS Relevant studies were identified in PubMed and Cumulative Index of Nursing and Allied Health Literature following strict eligibility criteria, including peer reviewed primary research, from 2010-2021, that examined rates of admissions, diagnoses, morbidity, and mortality of peripartum women requiring intensive care. Specialty ICU and countries with an overall performance score from the World Health Organization that placed them in the lower two-thirds deciles of all member countries were excluded. Fourteen articles, representing 9 countries, were reviewed by a single doctoral student. RESULTS Few obstetrics patients required intensive care. The majority of admissions and deaths occurred within the postpartum period. The most common admitting diagnoses were hemorrhage, hypertensive disorders of pregnancy, and sepsis. Mean mortality ranged from 0.2% to 9.7%. The most common causes of death were cardiovascular diseases and postpartum hemorrhage. CONCLUSIONS These women represent a truly specialized subset within the critical care population. Limitations include possible selection, confounding, and chronology biases; use of a single data extractor, and a relative dearth of relevant studies, originating in developed nations. CONCLUSIONS This review provided information on characteristics of the obstetric critical care population. Education and instituting early warning systems, formal debriefings, and standardization of protocols may assist in preparing critical care nurses in confidently caring for this population.