Study On The Effect Of Embryo Transfer Type On Clinical Pregnancy Outcome Of Frozen-thawed Embryo Transfer Patients Based On Propensity Score Matching

Purpose:Based on the propensity score matching to balance the confounding factors of two groups of infertile patients with different types of embryo transfer,to explore the effect of different types of embryo transfer on the clinical pregnancy rate of patients with frozen-thawed embryo transfer in hormonal replacement therapy cycle.Methods:The clinical data of 308 patients with infertility who underwent frozen-thawed embryo transfer(FET)in the Reproductive Medicine Center of Jiujiang Maternal and Child Health Hospital from June 2019 to December 2021 were retrospectively analyzed.According to the type of embryo transfer,they were divided into group A(cleavage stage embryos)and group B(blastocyst stage embryos).Then the related variables(age,luteinizing hormone LH,estradiol E2,progesterone P level on the transendothelial day,days of taking Estradiol Valerate Tablets,endometrial thickness,number of embryo transfers,etc.)were propensity score matched to 213 cases successfully.The clinical pregnancy outcomes of the two groups were comparatively analyzed.Result:1.Comparison of baseline data between the two groups before and after PSM matching: before matching,the age and the number of embryo transfer in group B were significantly lower than those in group A,while the serum LH and endometrial thickness on the day of endometrial transformation in group B were lower than those in group A,but there was no significant difference.The levels of E2 and P on the day of intimal transformation and the number of days of taking Estradiol Valerate Tablets in group B were higher than those in group A,and the difference was not statistically significant(P > 0.05).After matching,there was no significant difference in age,serum LH,E2,P levels,days of taking Estradiol Valerate Tablets,endometrial thickness and number of embryo transfer between group B and group A(P > 0.05).2.Comparison of pregnancy outcome between the two groups before and after PSM matching: compared with group A,the clinical pregnancy rate(clinical pregnancy rate,CPR)of group B was higher than that of group A before and after matching,and the difference was statistically significant.3.Analysis of the related factors affecting the clinical pregnancy rate of FET:After PSM matching,age,endometrial thickness and type of embryo transfer had significant effects on the pregnancy outcome of FET,while the levels of LH,E2,P on the day of endometrial transfer,the number of embryo transfer and days of taking Estradiol Valerate Tablets had no significant effect on the pregnancy outcome of FET(P > 0.05).multivariate Logistic regression analysis was performed with FET clinical pregnancy outcome as dependent variable and age,endometrial thickness and embryo transfer type as covariable.The results showed that age had significant effect on pregnancy outcome(P < 0.05).With the increase of age,the clinical pregnancy rate of FET decreased(OR=0.915,95%CI:0.875,0.957),that is,age was a risk factor for pregnancy success(OR < 1).Endometrial thickness also had a significant effect on pregnancy outcome.With the increase of endometrial thickness,the clinical pregnancy rate of FET increased(OR=1.231,95%CI:1.020,1.486),that is,the increase of endometrial thickness was the protective factor of pregnancy success(OR > 1).The type of embryo transfer also had a significant effect on the pregnancy outcome.The probability of clinical pregnancy with blastocyst FET was 2.223 times higher than that of blastocyst FET(OR=2.223,95%CI:1.369-3.609).Conclusion:In the frozen-thawed embryo transfer with artificial cycle(hormone replacement therapy cycle)as endometrial preparation,the type of embryo transfer had a significant effect on pregnancy outcome(P < 0.05).Blastocyst transfer may have a higher clinical pregnancy rate than cleavage embryo transfer.