Review of Endometrial Receptivity Array: A Personalized Approach to Embryo Transfer and Its Clinical Applications

Abstract

Successful outcomes of in vitro fertilization (IVF) rely on both the formation of a chromosomally normal embryo and its implantation in a receptive endometrium. Pre-implantation genetic testing for aneuploidy (PGT-A) has been widely accepted as a tool to assess the viability of an embryo. In 2011, the endometrial receptivity array (ERA) was first published as a tool to determine when the endometrium is most receptive to an embryo, commonly referred to as the “window of implantation” (WOI). The ERA uses molecular arrays to assess proliferation and differentiation in the endometrium and screens for inflammatory markers. Unlike PGT-A, there has been dissent within the field concerning the efficacy of the ERA. Many studies that contest the success of the ERA found that it did not improve pregnancy outcomes in patients with an already-good prognosis. Alternatively, studies that utilized the ERA in patients with repeated implantation failure (RIF) and transfer of known euploid embryos demonstrated improved outcomes. This review aims to describe the ERA as a novel technique, review the various settings that the ERA may be used in, such as natural frozen embryo transfer (nFET) and hormone replacement therapy frozen embryo transfer (HRT-FET), and provide a summary of the recent clinical data for embryo transfers in patients with RIF utilizing the ERA.

A Case Report on Endometrial Receptivity Array Test for Infertile Patient to Enhance Reproductive Outcomes

“…The ERA uses molecular arrays to "date" the endometrium and assess endometrial growth and differentiation. As a result, the ERA can help define a tailored WOI, which can then be used in a patient's FET plan to maximize the likelihood of a successful transfer [ 18 ].…”

A Comprehensive Review of the Endometrial Receptivity Array in Euploid Embryo Transfer Cycles

“…The precise timing of endometrial receptivity in euploid embryo transfer cycles holds significant importance in ART. Research indicates that aligning the timing of embryo transfer with the optimal window of endometrial receptivity, as determined by tests such as ERA, can significantly influence the success rates of embryo implantation and subsequent live births in patients undergoing IVF with euploid embryos [12][13][14].…”

“…Endometrial receptivity testing aims to pinpoint the ideal WOI tailored to each patient's characteristics through molecular analysis of the endometrium. This personalized approach aids in determining the most opportune moment for embryo transfer, potentially enhancing outcomes, particularly in patients with a history of RIF despite possessing known euploid embryos [12,14]. The research underscores the critical role of synchronizing the embryo and endometrium for successful implantation.…”

“…While the ERA test has demonstrated promise in improving outcomes, particularly in specific patient cohorts such as those with RIF, its universal effectiveness across all euploid embryo transfer cycles remains a topic of ongoing research and discussion. Further investigations, including adequately powered randomized clinical trials, are imperative to understand the impact of timed endometrial receptivity on the success rates of euploid embryo transfers in the context of IVF treatments [13,14].…”

Personalized embryo transfer guided by rsERT improves pregnancy outcomes in patients with repeated implantation failure

“…They found that ERA was capable of accurate diagnosis of the WOI ( 18 , 19 ). Several studies have shown that embryo transfer guided by ERA could avail RIF patients ( 19 – 21 ), whereas many research results have not found much benefit ( 22 – 24 ).…”