What is ERA?
Endometrial Receptivity Array is a method of assessing when the endometrium is most receptive for the embryo to implant. Each woman has a different window of implantation. Personalized embryo transfer increases the chances of conceiving a pregnancy. Research showed that 29% of patients were found to have displaced window of implantation. This test was performed on over 20,000 women in 54 countries all who were evaluated with ERA. Therefore, ERA is often helpful when we see recurrent implantation failure with a patient with good quality embryos and a morphologically normal endometrium.
What is the Science Behind ERA?
A molecular tool analyzes the expression of 236 genes that are involved in endometrial receptivity using Next Generation Sequencing Technology. The way it works is we first perform an ultrasound evaluation of the endometrium. We take a biopsy from the uterus during the estimated window of implantation (the time we would normally perform the embryo transfer). Then the analyzation of the endometrial biopsy is performed using Next Generations Sequencing Technology.
Interpreting the Results:
The results will come back as receptive or non-receptive.
Receptive – The endometrium is ideal for the embryo to implant. Proceed with the embryo transfer under the same conditions and same timeline in which the endometrial biopsy was performed.
Non-Receptive– The endometrium is not receptive for the embryo to implant. The embryo transfer window would be adjusted to earlier or later than when the biopsy was performed depending on the recommendations.
One study concluded that ERA improved pregnancy rates up to 85%, following personalized embryo transfers that were made after receiving ERA test results.
(SREI Prize Paper 2016. 0-115 Simon et al. on behalf of the ERA RCT Consortium).
A Genomic Diagnostic Tool for Human Endometrial Receptivity based on the Transcriptomic Signature. Fertil Steril.2011. 95(1)pp: 50-60, 60.e1-15. Díaz-Ginemo P, Horcajadas JA, Martínez-Conejero JA, Esteban FJ, Alamá P, Pellicer A, Simón C.
The endometrial receptivity array for diagnosis and personalized embryo transfer as a treatment for patients with repeated implantation failure.. Fertil Steril. 2013 Sep;100(3):818-24. doi: 10.1016/j.fertnstert.2013.05.004. Epub 2013 Jun 4.PubMed [journal]PMID:23756099. Ruiz-Alonso M, Blesa D, Díaz-Gimeno P, Gómez E, Fernández-Sánchez M, Carranza F, Carrera J, Vilella F, Pellicer A, Simón C.
The accuracy and reproducibility of the endometrial receptivity array is superior to histology as a diagnostic method for endometrial receptivity. Fertil Steril. 2013 Feb;99(2):508-17. doi: 10.1016/j.fertnstert.2012.09.046. Epub 2012 Oct 23. Díaz-Gimeno P, Ruiz-Alonso M, Blesa D, Bosch N, Martínez-Conejero JA, Alamá P, Garrido N, Pellicer A, Simón C.