The Impact Of Endometrial Preparation On Pregnancy Outcomes After Frozen Embryo Transfer In Patients With Tubal Infertility

Objective: In vitro fertilization-embryo transfer(IVF-ET/ICSI)or intracytoplasmic sperm injection(ICSI)is a common form of assisted reproductive technologies.Embryo transfer includes fresh embryo transfer and frozen-thawed embryo transfer.Frozen-thawed embryo transfer gradually occupies an increasing proportion in major reproductive centers,because it can avoid repeated ovarian stimulation and reduce the risk of ovarian hyperstimulation syndrome(OHSS).Endometrial preparation protocols include natural cycle,artificial cycle,ovulation stimulation cycle,and artificial cycle with Gn RH agonist pretreatment.The influence of different endometrial preparation regimens on pregnancy outcome is still controversial.At present,there is no guideline or expert consensus to conclude which is the best one.This study examines the impact of endometrial preparation on pregnancy outcomes after frozen embryo transfer in patients with tubal infertility.Methods: This study retrospectively analyzed the patients who underwent frozen-thawed embryo transfer due to tubal infertility at the Affiliated Hospital of Jining Medical College from January 1,2018 to December 30,2021 in the hospital.We selected 1483 patients according to the admission criteria.The main baseline data included male age,female age,duration of infertility,infertility type,body mass index,endometrial thickness and endometrial type on the day of transformation,the number of embryos transferred,the number of good quality embryos transferred and the types of embryos transferred.Outcome indicators include biochemical pregnancy rate,clinical pregnancy rate,ectopic pregnancy rate,pregnancy loss rate,premature delivery rate,live birth rate,weeks of gestation,newborn with macrosomia or low birth weight.The endometrial preparation protocols commonly used in people with tubal infertility is divided into three types: natural cycle,artificial cycle and ovulation stimulation cycle.Measurement data are expressed as mean± standard deviation,and counting data are expressed as numbers and percentages.Firstly,the baseline data and pregnancy outcome of the three groups were compared,and then the differences between the two groups were clarified by pairwise comparison.Then binary logistics regression was used to analyze the main factors affecting live births,and several possible confounding factors were adjusted.And the effects of three different endometrial preparation schemes on pregnancy outcome were compared.Finally,the effects of endometrial preparation regimens on pregnancy outcomes in patients with cleavage embryo transfer or blastocyst transfer were compared.Results: A total of 1483 cycles were studied,including 569 natural cycles,382 artificial cycles and 532 ovulation stimulation cycles.There were no statistical significances among the three groups in terms of male age,female age,body mass index(BMI),infertility type,infertility time,number of transferred embryos,number of transferred high-quality embryos and types of transferred embryos(P>0.05).Comparing the three groups,it was found that the thickness of endometrium in artificial cycle was significantly thicker than that in natural cycle,and the number of type A endometrium in ovulation induction cycle was significantly higher than that in artificial cycle(P<0.05).After comparing the three groups of endometrial preparation schemes,it was found that there was no significant difference in biochemical pregnancy rate,clinical pregnancy rate,ectopic pregnancy rate,pregnancy loss rate,premature delivery rate,live birth rate,macrosomia and low birth weight infants among the three groups.Female age(OR,0.97;95%CI,0.95-0.99),the number of highquality embryos transferred(OR,2.91;95%CI,1.34-6.31)and the type of embryos transferred(OR,3.00;95%CI,1.39-6.49)are independent influencing factors of live birth.Conclusion: The factors affect live birth rate included female age,the number of high-quality embryos transferred and the type of embryos transferred.There is no significant difference among biochemical pregnancy rate,clinical pregnancy rate,ectopic pregnancy rate,pregnancy loss rate,premature delivery rate,live birth rate,weeks of gestation,neonatal birth weight and low birth weight infants among the three endometrial preparation schemes.