Abstract: Objective To analyze the relationship between D-dimer/fibrinogen ratio (DFR) and in vitro fertilization and embryo transfer (IVF-ET) assisted pregnancy outcomes in infertile patients, and to provide experience for improving assisted pregnancy outcomes. 
Methods A retrospective analysis of 152 infertile patients who received IVF-ET treatment in the Reproductive Medicine Center, the People′s Hospital of Hechi City, was conducted. According to the outcome of assisted pregnancy, 93 infertility patients who obtained clinical pregnancy were included in the pregnancy success group, and the remaining 59 patients were included in the pregnancy failure group. The D-dimer (DD) and fibrinogen levels of human chorionic gonadotropin (HCG) in the early morning of the day for injection in the two groups were collected, and the DFR was calculated to analyze the correlation between DFR and IVF-ET assisted pregnancy outcome of infertile patients. 
Results The DD, fibrinogen, and DFR values in the pregnancy failure group were higher than those in the pregnancy success group, while the prothrombin time (PT), activated partial thromboplastin time (APTT), and thrombin time (TT) were shorter than those in the pregnancy success group, with significant differences (P＜0.05). Point-biserial correlation analysis showed that DFR was positively correlated with IVF-ET outcome in infertile patients (r=0.776, P=0.030). Logistic regression analysis showed that elevated DD, fibrinogen, and DFR were risk factors for IVF-ET assisted pregnancy failure in infertile patients (OR＞1, P＜0.05), while prolonged PT, APTT, and TT were protective factors for IVF-ET assisted pregnancy failure in infertile patients (OR＜1, P＜0.05). The receiver operating characteristic (ROC) curve was drawn, and the results showed that DD, fibrinogen, DFR, PT, APTT, and TT had certain predictive value for IVF-ET assisted pregnancy outcomes in infertile patients, but DFR had the optimal predictive value.  
Conclusion DFR is related to the IVF-ET assisted pregnancy outcome in infertile patients. Elevated DFR values can increase the risk of IVF-ET assisted pregnancy failure in infertile patients, and DFR values can provide important value for predicting IVF-ET assisted pregnancy outcomes in infertile patients. 

Key words: infertility, female, in vitro fertilization and embryo transfer, D-dimer, fibrinogen