Assessment of coagulation markers and decision curve analysis for predicting transfusions and hemostatic interventions in severe postpartum hemorrhage: A nationwide observational study in Japan

BACKGROUND: Postpartum hemorrhage (PPH) remains a major cause of direct obstetric mortality. We aimed to predict pregnant women with severe PPH, defined as cases requiring hemostatic interventions-such as transcatheter arterial embolization, hysterectomy, bimanual uterine compression, or intrauterine balloon tamponade-or blood transfusions. METHODS: This retrospective observational study utilized a large-scale database covering approximately 600 hospitals in Japan from 2014 to 2023. Women of ≥18 years of age, emergency hospitalized for placental abruption, amniotic fluid embolism, or peripartum hemorrhage were included. Laboratory test (platelets, fibrinogen, fibrinogen/fibrin degradation product [FDP], and prothrombin time-internationalized ratio [PT-INR]) results at admission and perinatal parameters were collected. The primary outcome was receiving hemostatic intervention or blood transfusion. Risk factors were assessed by logistic regression and non-linear regression analyses. Decision curve analysis (DCA) was used to compare Japanese obstetric scores with platelet adjustment and three existing obstetric disseminated intravascular coagulation (DIC) scores. RESULTS: /μL and 200 mg/dL, respectively. DCA revealed that the platelet-adjusted obstetric DIC score developed in this study showed the highest net benefit across most threshold probabilities when compared with the pregnancy-modified ISTH DIC score, the JAAM-2 DIC score, and the new Japanese obstetric DIC score, although the advantage was modest. CONCLUSION: Platelet counts and fibrinogen levels may be useful for identifying women with severe PPH who are at risk of requiring hemostatic interventions and transfusions.