Diagnosis of AFE, PA, and overt DIC

AFE was diagnosed using the Japanese AFE diagnostic criteria². The definition requires one of the following symptoms to develop during pregnancy or within 12 h of delivery and thereby need intensive care: (1) cardiac arrest, (2) severe bleeding of unknown origin within 2 h of delivery (≥ 1500 mL), (3) DIC, or (4) respiratory failure (Supplementary Table S2). In the present study, placental abruption was diagnosed clinically and pathologically with evidence of retroplacental hematoma. Its clinical features vary depending on the location of retroplacental hematoma and placental abruption area⁴⁴; therefore, we included PA patients complicated with DIC, which were consistent with Grade III in the classification of Page et al.³.This highly selected PA population that met with the following DIC diagnostic criteria was defined as severe PA (sPA) group in the present study. For the diagnosis of DIC, we employed modified DIC scores for pregnant women as defined by Erez³⁰ based on the International Society on Thrombosis and Haemostasis scoring system. The score was calculated using platelet count, prothrombin time difference in seconds (referring to prothrombin time-international normalized ratio [PT-INR]), and fibrinogen level. A total score of 26 or more was diagnosed as overt DIC (Supplementary Table S3). We employed the diagnostic criteria reported by the International Society for the Study of Hypertension in Pregnancy⁴⁵ to diagnose preeclampsia as a complication.