Objective To investigate the predictive value of serum human chorionic gonadotropin(HCG),D-dimer and granulocyte colony-stimulating factor(G-CSF)levels for pregnancy outcome in patients with re-current implantation failure(RIF).Methods A total of 80 RIF patients who underwent in vitro fertilization-embryo transfer in this hospital from May 2019 to May 2022 were selected as the research objects.According to the occurrence of adverse pregnancy outcomes,they were divided into a good pregnancy outcome group(48 cases)and a poor pregnancy outcome group(32 cases).The levels of serum HCG,D-dimer and G-CSF in RIF patients at different pregnancy stages(the day of pregnancy test,the first trimester,the second trimester and the third trimester)were detected.Spearman correlation was used to analyze the correlation between serum levels of HCG,D-dimer,and G-CSF and pregnancy outcomes.Multivariate Logistic regression was used to an-alyze the influencing factors of pregnancy outcome in patients with RIF.Receiver operating characteristic(ROC)curve was used to analyze the predictive value of serum HCG,D-dimer and G-CSF levels for pregnancy outcome in patients with RIF.Results Adverse pregnancy occurred in 32 cases of 80 patients with RIF,and preterm birth and intrauterine distress were the most common adverse pregnancy outcomes.The RIF patients with different stages of pregnancy serum HCG levels gradually decreased,serum D-dimer,G-CSF level in-creased(P<0.05).At different stages of pregnancy,the level of serum HCG in the poor pregnancy outcome group was lower than that in the good pregnancy outcome group(P<0.05),and the levels of serum D-dimer and G-CSF were higher than those in the good pregnancy outcome group(P<0.05).The level of serum HCG was negatively correlated with the adverse pregnancy outcome(r=-0.506,P<0.05),and the levels of ser-um D-dimer and G-CSF were positively correlated with the adverse pregnancy outcome(r=0.498,0.542,P<0.05).Multivariate Logistic regression analysis showed that HCG,D-dimer and G-CSF levels were the influ-encing factors of poor pregnancy outcome in patients with RIF(P<0.05).Serum HCG,D-dimer,G-CSF pa-tients with single and combined forecast RIF area under the curve of the pregnancy outcomes were 0.877,0.947,0.911 and 0.971,the sensitivity were 88.10%,88.10%,90.48%and 95.24%respectively,the specific-ity were 81.58%,97.37%,76.32%and 89.47%,respectively.The combined detection of the three markers could improve the prediction efficiency(P<0.05).Conclusion The combined detection of serum HCG,D-di-mer and G-CSF levels can effectively predict the pregnancy outcome of patients with RIF.