Objective:To analyze the subsequent assisted pregnancy outcomes of recurrent implantation failure (RIF) and find out the key influencing factors.Methods:A case-control study was conducted to analyze the clinical data of 640 patients who received embryo transfer assisted fertility in the Center for Reproductive Medicine of the First Affiliated Hospital of Zhengzhou University from January 2016 to June 2019 and were diagnosed with RIF and received subsequent assisted fertility treatment. The main outcome measures were the live birth rate and the time to pregnancy after diagnosis of RIF.Results:The live birth rate, the biochemical pregnancy rate, the clinical pregnancy rate and the abortion rate of the first cycle, the second cycle, the third and above cycle after a diagnosis of RIF were not significantly different (all P>0.05). The time to pregnancy after diagnosis of RIF of 344 patients who achieved live births was 5.00(3.13, 8.52) months. After adjusting for confounding factors by using multivariate logistic regression, the results showed that the cumulative live birth probability of blastocyst transfer was significantly higher than that of cleavage embryo transfer [ P=0.002, RR (95% CI)=1.492(1.158-1.923)]; the cumulative live birth probability of patients less than 35 years old was significantly higher than older patients (≥35 years old)[ P=0.013, RR (95% CI)=0.694(0.521-0.925)]; the cumulative live birth probability of patients with endometrial thickness ≥8 mm on the embyro transfer day was significantly higher than that of patients with endometrial thickness <8 mm [ P=0.016, RR (95% CI)=1.943(1.132-3.335)]; compared with patients with 0 [ P=0.001, RR (95% CI)=0.625(0.474-0.825)] or 2 and more [ P=0.003, RR (95% CI)=0.414(0.233-0.736)] biochemical pregnancy in the RIF cycles, the cumulative live birth probability of patients with history of only 1 biochemical pregnancy in the RIF cycles was significantly higher. Conclusion:The type of embryos transferred, age, endometrial thickness on the embyro transfer day and the history of biochemical pregnancy in the RIF cycles are independent factors for subsequent cumulative live birth probability in RIF patients. Blastocyst transfer should be selected as much as possible, and fertility treatment should be performed as soon as possible through reasonable cycle management, the history of only 1 biochemical pregnancy in the RIF cycles heralds a better live birth outcome in the subsequent cycles of RIF.

Objective:To analyze the subsequent assisted pregnancy outcomes of recurrent implantation failure (RIF) and find out the key influencing factors.Methods:A case-control study was conducted to analyze the clinical data of 640 patients who received embryo transfer assisted fertility in the Center for Reproductive Medicine of the First Affiliated Hospital of Zhengzhou University from January 2016 to June 2019 and were diagnosed with RIF and received subsequent assisted fertility treatment. The main outcome measures were the live birth rate and the time to pregnancy after diagnosis of RIF.Results:The live birth rate, the biochemical pregnancy rate, the clinical pregnancy rate and the abortion rate of the first cycle, the second cycle, the third and above cycle after a diagnosis of RIF were not significantly different (all P>0.05). The time to pregnancy after diagnosis of RIF of 344 patients who achieved live births was 5.00(3.13, 8.52) months. After adjusting for confounding factors by using multivariate logistic regression, the results showed that the cumulative live birth probability of blastocyst transfer was significantly higher than that of cleavage embryo transfer [ P=0.002, RR (95% CI)=1.492(1.158-1.923)]; the cumulative live birth probability of patients less than 35 years old was significantly higher than older patients (≥35 years old)[ P=0.013, RR (95% CI)=0.694(0.521-0.925)]; the cumulative live birth probability of patients with endometrial thickness ≥8 mm on the embyro transfer day was significantly higher than that of patients with endometrial thickness <8 mm [ P=0.016, RR (95% CI)=1.943(1.132-3.335)]; compared with patients with 0 [ P=0.001, RR (95% CI)=0.625(0.474-0.825)] or 2 and more [ P=0.003, RR (95% CI)=0.414(0.233-0.736)] biochemical pregnancy in the RIF cycles, the cumulative live birth probability of patients with history of only 1 biochemical pregnancy in the RIF cycles was significantly higher. Conclusion:The type of embryos transferred, age, endometrial thickness on the embyro transfer day and the history of biochemical pregnancy in the RIF cycles are independent factors for subsequent cumulative live birth probability in RIF patients. Blastocyst transfer should be selected as much as possible, and fertility treatment should be performed as soon as possible through reasonable cycle management, the history of only 1 biochemical pregnancy in the RIF cycles heralds a better live birth outcome in the subsequent cycles of RIF.