| With the rapid development of embryo vitrification and culture technology,the frozen-thawed embryo transfer（FET）has become an important part of the assisted reproductive technology.In recent years,many elder women have been unable to carry out fresh cycle transplantation due to the lack of available embryos,endometrium and hormone abnormalities,and FET has become an important mean of pregnancy.With the growth of age,the fertility of the elder patients has decreased linearly and the embryo has been more valuable.It is particularly important to study the endometrial preparation plan of the elder patients for frozen thawed embryo transfer to get better clinical outcomes.At present,the commonly used endometrial preparation programs include letrozole induction,natural cycles and hormone replacement therapy.Although there are a number of studies dedicated to compare the pregnancy outcomes of three endometrial transplant programs,but the results are inconclusive.The purpose of this study was to retrospectively analyze the effect of different endometrial protocols on FET pregnancy outcomes in elder women with the aim of providing a suitable endometrial preparation program for elder patients.ObjectiveTo compare the pregnancy outcomes of frozen-thawed embryo transfer（FET）in elder patients under different endometrial protocols.Materials and Methods1.Objective:The date of 1482 FET cycles in elder patients from January 2015to January 2017 in Reproductive Medicine Center of the Third Affiliated Hospital of ZhengZhou university were analyzed retrospectively.2.Methods:According to the endometrial preparation scheme and the type of embryo transferred,all subjects were divided into six groups:transferring cleavage-stage embryo in LE group on ovulation induction cycle（group L3,n=84）,transferring blastocyst in LE group on ovulation induction cycle（group L5,n=43）,transferring cleavage-stage embryo in natural cycle（group N3,n=377）,transferring blastocyst in natural cycle（group N5,n=210）;transferring cleavage-stage embryo in hormone replacement treatment（HRT）cycle（group H3 n=565）and transferring blastocyst in HRT cycle（group H5,n=203）.Embryo implantation rate,clinical pregnancy rate,ectopic pregnancy rate,abortion rate,premature birth rate,live birth rate and multiple pregnancy rate were compared among the three kinds of endometrial preparation scheme for transferring cleavage-stage embryo and blastocyst respectively.3.Statistics approach:The data were analyzed by SPSS 21.0 statistical software,the measurement data were described by mean±standard deviation or median,and the count data was described by percentage.The three groups of measurement data were analyzed by one-way ANOVA or Mann-Whitney test and LSD was performed to see the difference between two independent samples.Count data comparison of three Group were analyzed by R×C Chi-square test.Correlative factors were analyzed using two-class Logistic analysis.P<0.05 for the difference was statistically significant.Results1.Baseline date comparison:there were no significant differences in female age,duration of infertility,BMI,base E2,FSH,LH,the number of transferred embryos and high quality embryo rate in each group of patients（P>0.05）,Endometrial thickness in the HRT group was significantly lower than those of the letrozole and the natural cycle groups on the day of embryo transfer（P<0.05）.2.When the cleavage embryos were transferred,embryo implantation rate and clinical pregnancy rate in the natural cycle group were higher than those in the HRT cycle groups（P<0.05）,but there were no significant differences in those between the letrozole and the natural cycle groups（P>0.05）.There were no significant differences in the rates of ectopic pregnancy,premature birth,premature birth,live birth and multiple pregnancy between three groups（all P values>0.05）3.When the cleavage embryos were transferred,embryo implantation rate in the natural cycle group was higher than that in the HRT cycle groups（P<0.05）,but there was no significant difference in it between the letrozole and the natural cycle groups（P>0.05）.There were no significant differences in clinical pregnancy,ectopic pregnancy,premature birth,premature birth,live birth and multiple pregnancy rates between three groups（P>0.05）.4.Clinical pregnancy was set as the dependent variable,with independent variables being female age,duration of infertility,BMI,endometrial thickness on the day of embryo transfer and the number of transferred embryos.The results showed that female age（OR=0.834,95%CI:0.804-0.866）was a risk factor for pregnancy.endometrial thickness（OR=1.162,95%CI:1.091-1.239）and number of transferred embryos（OR=1.280,95%CI:1.016-1.612）were a protective factor for pregnancy.Conclusions1.When the elder patients with frozen-thawed embryo selecting endomembrane preparation options,the natural cycle may be better than the hormone replacement treatment program.2.During the preparation of endometrium,letrozole can get similar pregnancy outcome to natural cycle.It may be an option for endometrial preparation of frozen-thawed embryos in elder patients.3.In FET patients,female age,endometrial thickness on the day of embryo transfer and the number of embryos transferred are independent factors of clinical pregnancy. |
