Timing Measurement Add Human Chorionic Gonadotropin For Luteal Phase Support In Repeated Implantation Failure Patients And Mechanism Research

Background:Repeated implantation failure（RIF）is a special type of disease in assisted reproductive therapy^[1].Although there are many reports about RIF,there is no unified standard^[2].Orvieto^[3]believe that RIF is a high-quality embryo transplantation for 3consecutive cycles without obtaining a clinical pregnancy,and Zeyneloglu^[4]believe that RIF is a high-quality embryo transplantation for 3 consecutive cycles without obtaining a clinical pregnancy.The incidence of RIF in in vitro fertilization-embryo transfer is10%to 15%.The etiology of RIF is 1/3 related to embryo quality and 2/3 is related to maternal factors.Current clinical approaches to RIF include:improving embryo quality and improving endometrial receptivity.Treatment methods to improve embryo quality include:PGT technology,PGT-A,ZIFT and DFI reduction,IVF regimen change,adjuvant drug treatment,etc.And methods to improve endometrial receptivity include:hormonal drug therapy（estrogen,progesterone,bromocryptin Ting）,adjuvant drug therapy（vitamin D,aspirin,low molecular weight heparin,microbial agents,antibiotics,etc.）,immunotherapy（prednisone,active immunity,passive immunity,granulocyte colony stimulating factor,etc.）,assisted reproductive therapy（intrauterine Membrane opening period detection,etc.）,surgical treatment（hysteroscopy,laparoscopy）,Chinese medicine treatment,stem cell treatment and psychological treatment.These methods can treat some RIF patients,but there are still many fertility problems in RIF patients that cannot be solved.The previous research of our group found that^[5],there was a significant difference between luteinizing hormone（LH）in the luteal phase of patients with recurrent miscarriage compared with the control group,and further found that the hormone level of luteal phase D2 also exists in some RIF patients abnormal manifestations,in addition to the known abnormal manifestations of estrogen and progesterone,luteinizing hormone also exhibits abnormalities（all patients draw blood at8:00 am）.In light of this,it is necessary to explore a corpus luteum support program for patients with low luteinizing hormone RIF.Because the current market price of LH is high and the content of active ingredients is low,the direct addition of exogenous LH to supplement luteinizing hormone brings great economic pressure to patients and the effect is poor.Because theαsubunit structures of LH and HCG are the same,βthe subunits are similar in structure,they act on the same receptor,so consider replacing exogenous LH with exogenous HCG to make up for the lack of luteinizing hormone,but the addition of HCG will interfere with the detection of HCG value on pregnancy day.Designing an economical and practical luteal phase support scheme using HCG will solve this part of the RIF problem.Objective:Based on previous clinical studies,a new luteal support plan for patients with low luteinizing hormone RIF is proposed to improve their clinical pregnancy rate and live birth rate and preliminary exploration of its mechanism.Methods:A retrospective analysis was performed on 84 people who assisted the pregnancy at the Assisted Reproductive Medicine Center of The Sixth Medical Center of General Hospital of Chinese People’s Liberation Army from August 20,2014 to December 31,2017.（This project is a retrospective observational study.The project started in December 2018.Since the follow-up of live birth takes 1 year,the time point of observation is December 31,2017.）All patients agreed to undergo IVF-ET fertility treatment.Common characteristics of the patients included:a.Repeated transplantation failure（RIF）,b.Aged≥35 years old and<45 years old,c.D2 LH≤5IU/L.The clinical data of the patients after thawing transplantation were analyzed.According to the different luteal phase support methods,the patients were divided into Observation groups:43 patients were given HCG luteal support treatment on the day after transplantation（HCG 500 IU 1 time/day x 7-10 days to blood draw day from transplantation day）,and the control group was not given 41 HCG luteal support treatment.The biochemical pregnancy rate,ectopic pregnancy rate,clinical pregnancy rate,multiple pregnancy rate,abortion rate and live birth rate were compared between the two groups.Six patients in the RIF were selected for full exon detection and the genetic results of the patients were analyzed.Result（s）:84 patients underwent 116 cycles,44 patients in the experimental group underwent 57 cycles,and 41 patients in the control group underwent 59 cycles.There were no significant differences in age,body mass index,Basal Follitropin Beta level,Basal Lutropin Alfa level,Basal estradiol level,Basal progesterone level,type of infertility,duration of infertility,endometrial preparation plan,endometrial thickness and typing on the conversion day,endometrial thickness and typing on the Transplantation Day,embryo number and superior embryo number between the two groups（p>0.05）,there was no significant difference in ectopic pregnancy rate,multiple pregnancy rate and abortion rate between the two groups（p>0.05）,the clinical pregnancy rate(51.2%（22/43）in the experimental group,29.3%（12/41）in the control group and the live birth rate（46.5%（20/43）in the experimental group and 24.4%（10/41）in the Control Group）were significantly different（p<0.05）.Many genes with potentially harmful mutations were detected in 6 patients with repeated transplant failures,and these genes were significantly enriched during embryo implantation or endometrial receptivity.Among them,5 patient sites were enriched to the ECM receptor interaction pathway.Most of these gene mutations are missense mutations,which usually affect protein biological activity.Conclusion（s）:1.It is clear that low luteinizing hormone level in the luteal phase is one of the reasons for repeated transplant failures;2.Regularly measuring the luteal support program with HCG can increase the clinical pregnancy rate and live birth rate of patients with RIF;3.The low luteinizing hormone level is D2 blood LH≤5IU/L as the diagnostic criterion;4.The pathogenesis of patients with low luteinizing hormone RIF,it is initially inferred from the genetic level that it affects endometrial receptivity and causes RIF through the ECM receptor interaction pathway;5.Moderate impairment of pregnancy related pathways by genomic analysis also explains the potential molecular mechanism of our subclinical phenotypes.