Effects Of GnRH Agonist As Luteal Support On Endometrial Receptivity In ART Cycles

In assisted reproductive technology,endometrial receptivity is the key of embryo implantation.Endometrial receptivity defects are the main causes of the failure of embryo implantation,accounting for about 2/3.To improve the endometrial receptivity and increase embryo implantation rate and clinical pregnancy rate is needed to be solved urgently in the field of reproductive problems.In vitro fertilization and embryo transfer(IVF-ET)cycle,must inadequate luteal phase support need to be provided.HCG is one of the most common and curative effect of luteal support scheme,it can lead to OHSS and its application is limited.In recent years,the study found that administration of GnRH-a in luteal support can improve the outcome of pregnancy in IVF-ET cycles,as far its being known and popular as a luteal support drugs;also GnRH-a can induce pituitary secretion of LH and or can directly effect on local endometrium,even in embryonic surface receptors(GnRH-R)play a role,but its mechanism of action in the luteal support are not yet clear,obstacles on its clinical application.Aim of the research: Exploration of effect and mechanism of GnRH-a in IVF-ET cycles during luteal support on endometrial receptivity,generalizing theoretical basis for its clinical application.Methods: From 2015 June to October the 34 patients of IVF / ICSI cycles in the Reproductive Medical Center of Shanxi Women and Children Health Hospital undergoing long stimulation protocol patients were divided into three groups according to the different luteal support methods: GnRH-a group(11 cases),control group(13 cases)with no luteal support;HCG group(10 cases).All the clinic data and information of these patient subjects in these 3 groups are interviewed randomly and collected.Following these three groups of patients with various clinical data,the endometrial biopsy collection planter sample window and pinopodes observed under the scanning electron microscope.Using gene expression microarray,genes were screened and verified by qPCR and evaluation of the influence of GnRH-a on endometrial receptivity was done.Result: There was no statistical difference in the three groups of patients(P > 0.05).Cell pinopodes development degree: GnRH-a group complete development(81.8%,P < 0.05),the control group,HCG group the complete development proportion is less(0%,20.0%);coverage area score: GnRH-a group(2.45,P < 0.1),HCG group(2.70,P < 0.05)were higher than those of control group(2.00).Chip screening and receptivity and by qPCR to verify the difference expression genes include: three types of related genes ACVR1 C and LPAR3,DKK1,three types of negative related gene PTX3,TGF ? 2,SFRP4.The implantation related genes ACVR1 C and LPAR3,DKK1 were up-regulated in GnRH-a group and HCG group than those in the control group;while negative related genes PTX3,TGFB2 and SFRP4 were lower in GnRH-a group and HCG group than those in the control group showed a downward trend.Conclusion: Application of GnRH-a in IVF helps as luteal phase support to improve the endometrial receptivity,and essential to enhance the reproductive outcome in IVF cycles.The possible mechanism of action is that GnRH-a promoting the development of pinopodes and regulating the expression of related genes to improve the receptivity of endometrium to the embryo.