Endometrial receptivity array: Clinical application

Abstract

Human implantation is a complex process requiring synchrony between a healthy embryo and a functionally competent or receptive endometrium. Diagnosis of endometrial receptivity (ER) has posed a challenge and so far most available tests have been subjective and lack accuracy and a predictive value. Microarray technology has allowed identification of the transcriptomic signature of the window of receptivity window of implantation (WOI). This technology has led to the development of a molecular diagnostic tool, the ER array (ERA) for diagnosis of ER. Use of this test in patients with recurrent implantation failure (RIF) has shown that the WOI is displaced in a quarter of these patients and use of a personalized embryo transfer (pET) on the day designated by ERA improves reproductive performance. Our results in the Indian population revealed an endometrial factor in 27.5% RIF patients, which was significantly greater than the non-RIF group 15% (P = 0.04). After pET, the overall ongoing pregnancy rate was 42.4% and implantation rate was 33%, which was at par with our in-vitro fertilization results over 1-year. We also performed ERA in patients with persistently thin endometrium, and it was reassuring to find that the endometrium in 75% of these patients was receptive despite being 6 mm or less. A pregnancy rate of 66.7% was achieved in this group. Though larger studies are required to validate these results ERA has become a useful tool in our diagnostic armamentarium for ER.

Keywords: ERA; Endometrial receptivity; in-vitro fertilization; recurrent implantation failure; thin endometrium.

Figure 1

Principal component analysis of human endometrium throughout the development of the luteal phase in natural (LH + n) and controlled ovarian stimulation cycles (human chorionic gonadotropin + n). Reprinted with permission Horjcadas et al. J Clin Endocrinol Metab, November 2008, 93(11):4500-10

Figure 2

Evolution of endometrial tissue over time and the gene expression profile at each given stage. Heat map showing ERA gene expression profiles in each endometrial cycle stage (PE, prereceptive, receptive, and postreceptive) and the major biological functions regulated in each of these phases. Reprinted with permission from Garrido-Goˇmez. Genomics of endometrial receptivity. Fertil Steril 2013

Figure 3

The predictor and clustering analysis indicating “nonreceptive” samples. Courtesy IVIOMICS

Figure 4

Principal component analysis for personalized Window of implantation. ERA R P + 5. Courtesy IVIOMICS