Abstract:

Objective To explore the effective ways for improving the outcome of frozen ⁃thawed embryo transfer（TET）in endometriosis patients with repeated implantation failure（RIF）. Methods The clinical data on endometriosis patients with RIF following total 81 TET cycles from January 2016 to December 2020 were retrospec⁃ tively analyzed. According to different protocols of endometrial preparation，the patients were divided into natural cycle（NC）group，ovulation induction（OI）group，hormone⁃replacement therapy（HRT）group，and down⁃regulated HRT group. The baseline information and outcomes of assisted conception were compared among these groups. The factors influencing clinical pregnancyoutcome were analyzed by multivariate logistic regression. Results The number and type of transferred embryos were the factors affecting the pregnancy outcomes（P < 0.05）. The implantation rate of blastocysts from non⁃high quality embryos was significantly higher than that of high⁃quality cleavage embryos（P < 0.05）. The mean number of transferred embryos was significantly higher in HRT group than NC group（P < 0.05）. The rates of clinical pregnancy and implantation were higher in HRT group than NC group and down⁃regulated HRT group，but there were no significant differences（P > 0.05）. The rates of multiple pregnacy，early abortion，and ecto⁃ pic pregnancy did not differ significantly among the four groups（P > 0.05）. According to differences in the type of transferred embryos，there were no statistical differences in the rates of high⁃quality embryo and clinical pregnancy among the three groups（P > 0.05）. No statistical differences were found in the impact of presence or absence of sur⁃ gical treatment prior to IVF/ICSI on the clinical pregnancy outcomes（P > 0.05）. Conclusions The endometriosis patients with RIF receiving differentendometrial protocols were comparable in their pregnancy outcomes. For improv⁃ ing the clinical pregnancy rate，the number of transplanted embryos can appropriately be increased or the blastocyst should be transplanted if necessary.

Key words:

repeated implantation failure, endometriosis, down ? regulated HRT, frozen ?thawed embryo transfer