The Analysis Of Correlation Between Different Endometrial Preparation In Non-PCOS Patients Undergoing Vitrified Single Blastocyst Transfer And Pregnancy And Perinatal Outcomes

Background:As an extension of assisted reproductive technologies(ART),frozen thawed embryo transfer(FET)technology freezes the surplus embryos which obtained by controlled ovulation induction and then transfers them at a selected time.This protocol improves the utilization rate of embryos and the cumulative pregnancy rate,which is an important way to preserve fertility.During the process of FET,the key to determine whether the embryo can be implanted and developed is the quality and the development stage of the embryo,the endometrial environment,and the synchronization with between each other.Under the standardized embryo culture in assisted reproduction laboratories,the appropriate endometrial preparation program plays a decisive role for improving the synchronization between endometrium and embryo.At present,the commonly used endometrial preparation schemes in clinic include natural cycle(NC)scheme and hormone replacement therapy(HRT)scheme.NC scheme is to arrange embryo transfer after natural ovulation or human chorionic gonadotropin(hCG)induced ovulation.While HRT scheme uses estrogen(E2)and progesterone(P)to simulate the physiological state of endometrial environment.Embryo transplantation is arranged after the endometrium is transformed into secretory phase.Up till now,many randomized controlled trials(RCTs)believe that there is no significant difference in pregnancy outcomes between the two regimens,but some retrospective cohort studies have found that the clinical pregnancy rate of patients using HRT regimen is significantly lower than that of NC regimen,while the early miscarriage rate is significantly increased.The risk of perinatal complications such as hypertension disorders of pregnancy and postpartum hemorrhage is also significantly increased after HRT regimens.Which intimal preparation scheme is the optimal choice in clinical work?The definite answer can be acquired under certain conditions.In order to the further guide the clinical work and to improve the pregnancy outcome,we conducted this topic to explore the optimal scheme in the population of non-polycystic ovary syndrome.Objective:This study investigated the effects of different endometrial preparation schemes on pregnancy outcomes and obstetric labor complications during vitrified single blastocyst transfer(VSBT).Study design:The baseline data and pregnancy follow-up data of patients with the first artificial insemination/intracytoplasmic sperm injection(IVF/ICSI)-VSBT from March 2015 to November 2019 were extracted from the electric medical record system of the Hospital for Reproductive Medical Affiliated to Shandong University and were analyzed retrospectively.A total of 2342 cycles were included.Patients were divided into NC group and HRT group according to different endometrial preparation schemes.The main observation index was the live birth rate.The clinical pregnancy rate,the early miscarriage rate,the incidence of obstetric labor complications was taking as the secondary observation index.Logistic regression analysis was used to correct the confounding factors affecting the observation indexes.P<0.05 was considered statistically significant.Results:It was found that compared with NC regimen,HRT regimen had lower clinical pregnancy rate(69.60%vs 63.83%,P=0.033)and live birth rate(59.22%vs 49.14%,P<0.001).At the same time,the premature birth rate(9.15%vs 14.22%,P=0.003),cesarean section rate(61.89%vs 78.01%,p<0.001),and the incidence of HDP(3.28%vs 11.44%,P<0.001)increased.After multiple logistic regression,we found that the clinical pregnancy rate(aOR:0.763,95%CI:0.611-0.952,P=0.017)and live birth rate(aOR:0.75,95%CI:0.621-0.904,P=0.003)in HRT group were lower than those in NC group,while the cesarean section rate and the incidence of HDP(aOR:3.076,95%CI:1.779-5.317,P<0.001)were higher than those in NC group.Conclusions:In patients undergoing vitrified thawed single blastocyst transfer,compared with HRT regimen,using NC regimen for endometrial preparation can obtain better pregnancy outcomes and obstetrics delivery outcomes.