Effect of estrogen levels on the day of embryo transfer in FET cycle on pregnancy outcome in patients with infertility
ZHANG Wenyan
JIANG Bo
LI Xiaorong
FENG Yahong
WANG Qinjiao
QIN Ling
ZHONG Jiawen
Abstract：Objective To analyze the effect of estradiol(E2)levels on the day of embryo transfer in the frozen em-bryo transfer(FET)cycle on pregnancy outcomes in infertile patients.Methods Totally 323 infertile patients who re-ceived FET and had endometrial preparation with hormone replacement therapy(HRT)were divided into three groups based on E2 levels on the day of embryo transfer:Group A(n=45,E2<100 pg/mL),Group B(n=187,E2 100-300 pg/mL),and Group C(n=91,E2>300 pg/mL).The pregnancy outcome-related indicators,including clinical pregnancy rate,biochemical pregnancy rate,early miscarriage rate,multiple pregnancy rate,and live birth rate,were compared among the three groups.Multivariate Logistic regression was used to analyze the effect of E2 on the day of embryo transfer on pregnancy outcomes(clinical pregnancy and live birth).Results The clinical pregnancy rates in the Groups A,B,and C were 33.3%,41.7%,and 26.4%,respectively,and the live birth rates were 73.3%,78.2%,and 62.5%,respectively,with Group B>Group A>Group C(all P<0.05).There were no statistically significant differences in biochemical pregnancy rate,early miscarriage rate,or multiple pregnancy rate among the three groups(all P>0.05).Among the 323 infertile patients,117 achieved clinical pregnancy and 206 did not.The E2 level on the day of embryo transfer was lower in those who achieved clinical pregnancy than in those who did not,and E2 was an independent risk factor for clinical pregnancy after FET in infertile patients[P=0.009,OR(95%CI):0.996(0.993～0.999)].Among the 117 infertile patients who achieved clinical pregnancy after FET,87 had live births and 30 did not.The E2 level on the day of embryo transfer was lower in those who had live births than in those who did not,and excessively high E2 on the day of embryo transfer was an independent risk factor for live birth in infertile patients who achieved clinical pregnan-cy after FET[P=0.024,OR(95%CI):0.997(0.994～0.999)].Conclusion Infertile patients with E2 levels of 100-300 pg/mL on the day of embryo transfer have higher clinical pregnancy rates and live birth rates.Excessively high E2 levels on the day of embryo transfer are not conducive to clinical pregnancy and live birth in infertile patients.
Keywords：estrogenthe day of embryo transferfrozen embryo transplantationpregnancy outcomeinfertility
Publication Date：2025-03-25
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：5( 17-21 )