['Multiple scoring systems exist to identify inpatients who are at risk for clinical deterioration. None of these systems have been evaluated in an obstetric population. We examined the Systemic Inflammatory Response syndrome (SIRS) and Modified Early Warning score (MEWS) criteria in pregnant women with chorioamnionitis.', 'This was an 18-month retrospective analysis of patients with chorioamnionitis. SIRS and MEWS scores were calculated; clinical outcomes were ascertained, and test characteristics were calculated for the primary outcome of sepsis, intensive care unit transfer, or death.', 'Nine hundred thirteen women with chorioamnionitis were identified. Five women experienced sepsis; there was 1 death. Five hundred seventy-five of the 913 women (63%) met SIRS criteria (95% confidence interval, 59.8-66.2%; positive predictive value, 0.9%). Ninety-two of the 913 women (10.3%) had a MEWS score of ≥ 5 (95% confidence interval, 8.3-12.2%; positive predictive value, 0.05%).'] Do existing models fail to predict sepsis in an obstetric population with intrauterine infection?