Objective To explore the predictive value and the correlation of late pregnancy coagulation function indicators in postpartum hemorrhage of gestational diabetes mellitus(GDM).Methods One hundred and twenty pregnant women with GDM were selected as the research subjects,they were divided into the observation group(postpartum hemorrhage,n=24)and the control group(no postpartum hemorrhage,n=96)based on the presence postpartum hemorrhage.Prothrombin time(PT),activated partial thrombin time(APTT),thrombin time(TT),fibrinogen(FIB)and D-dimer(D-D)were compared between the two groups in late pregnancy.The receiver operating curve(ROC)was drawn to analyze the predictive value of the above indicators and combined indicators for postpartum hemorrhage in GDM.The Pearson method was used to analyze the correlation between PT,APTT,TT and D-D and the volume of postpartum hemorrhage.Results Compared with the control group,the observation group showed prolonged PT,APTT and TT,decreased FIB,and increased D-D,the differences were statistically significant(all P<0.05).The ROC curve analysis showed that plasma PT,APTT,TT,FIB,and D-D can all predict postpartum hemorrhage in GDM,with the best combined efficacy of the five.The area under the curve was 0.907(0.838,0.968),and the sensitivity and specificity were 85.5%and 92.4%,respectively.The Pearson correlation analysis showed that plasma PT,APTT,TT and D-D were significantly positively correlated with the amount of postpartum hemorrhage in GDM(r values were 0.745,0.759,0.774 and 0.789 respectively,P<0.00l)while plasma FIB was significantly negatively correlated with the amount of postpartum hemorrhage in GDM(r values were-0.784,P<0.001).Conclusion In GDM patients with postpartum hemorrhage,abnormalities in plasma PT,APTT,TT,FIB,and D-D levels in late pregnancy are observed.These indicators are significantly correlated with the volume of postpartum hemorrhage.The combination of these five indicators can effectively predict postpartum hemorrhage in GDM,suggesting potential for clinical application.