P–297 Endometrium receptivity test in patients with failed embryo implantation
Authors: Makhmudova G 
Published: August 2021

Abstract

Study question
Studying the receptivity of the endometrium for improving the synchronicity between the embryo and the condition of the endometrium.

Summary answer
Determination of the level of endometrial receptivity with PGT may significantly increase the effectiveness of IVF in patients with recurrent implantation failure

What is known already
Modern approach to the treatment of patients with recurrent implantation failure, using assisted reproductive technologies imply preimplantation genetic testing (PGT) of embryos for chromosomal abnormalities. However, in some cases, even with the transfer of a genetically complete embryo, pregnancy does not occur. A possible reason is a violation of embryo implantation due to a shift in the period of the “implantation window” . The ERA (Endometrium Receptivity Assay) is a personalized molecular genetic test specifically designed to analyze the level of endometrium receptivity for determine the period of the “implantation window”.

Study design, size, duration
ERA test is carried out for patients with idiopathic infertility, in cases where repeated transfer of a genetically complete embryo does not lead to implantation and pregnancy: at least three attempts in the case of women under 37 years old and two attempts - for older women (without pathological morphological changes in the endometrium). The test was performed in a cycle with hormone replacement therapy (HRT) or a natural cycle.

Participants/materials, setting, methods
Were investigated the endometrial Pipell biopsy specimen in a cycle of hormone replacement therapy (HRT) or a natural cycle. Endometrial examination was implemented using the Endometrium Receptivity Assay, the analysis of mRNA of 238 genes was carried out, which showed a difference in the level of expression when analyzing samples of prereceptive, receptive and postreceptive endometrium.

Main results and the role of chance
The results of the studies of the level of endometrial receptivity revealed a shift in the period of the “implantation window” in 28% of patients. The results obtained make it possible to carry out the transfer of embryos in an individual order for each patient, taking into account the data on the level of receptivity of the endometrium, which makes it possible to implement the so-called Personalized Embryo Transfer (pET) principle. In 72% of cases, the study showed the “receptive” status of the endometrium. The result means that the period of the “implantation window” for a particular type of cycle falls on the moment of biopsy and this period of time is the most favorable for implantation of the embryo. For patients from this group, embryo transfer is carried out at the next repetition of the cycle option selected for the study of receptivity, while the blastocyst transfer occurs on the same day of the cycle when the endometrial biopsy was performed.

Limitations, reasons for caution
The ERA test is unique technique.
Wider implications of the findings: Using the ERA test allow to determine the state of maturity of the endometrium. Unlike other methods for receptivity of the endometrium, the ERA test allows not only to accurately determine the period of the “implantation window”, but also to reliably predict its displacement to an earlier or later time.

Trial registration number
Not applicable