Maternal Severity and Diagnostic Validity of the Revised Japanese Criteria for Obstetric Disseminated Intravascular Coagulation: A Retrospective Observational Study

AIM: In Japan, the diagnostic criteria for obstetric disseminated intravascular coagulation (DIC) were revised in 2024. This study aimed to evaluate the clinical utility of the revised obstetric DIC criteria, defined as the ability to identify patients at higher risk of severe maternal outcomes at presentation. METHODS: This single-center retrospective cohort study included women who delivered at ≥ 22 weeks of gestation and were transferred for primary postpartum hemorrhage (PPH) between April 2016 and March 2025. Women were compared according to obstetric DIC status and the presence of severe maternal outcomes to evaluate the ability of the revised criteria to identify patients with severe outcomes at presentation. RESULTS: Among women transferred for primary PPH, 18% were diagnosed with obstetric DIC. Severe maternal outcomes occurred more frequently in the obstetric DIC group than in the non-obstetric DIC group (55% vs. 24%; p = 0.002; relative risk, 2.27; 95% CI, 1.47-3.51). Fibrinogen levels were significantly lower in the severe group (163 mg/dL vs. 241 mg/dL, p < 0.001), whereas fibrin/fibrinogen degradation product (FDP) (85.6 μg/mL vs. 32.4 μg/mL, p = 0.61) and D-dimer (11.2 μg/mL vs. 9.5 μg/mL, p = 0.083) levels showed no significant differences. CONCLUSIONS: Although the revised obstetric DIC criteria better reflect the underlying pathophysiology by incorporating hyperfibrinolysis, severe maternal outcomes were still observed in women without obstetric DIC, likely reflecting dilutional coagulopathy. These findings suggest that fibrinogen may serve as an indicator of maternal severity, complementing markers of enhanced fibrinolysis.