Unlocking the WOI wonder:
ER Map® empowers personalized embryo transfer


Recent controversies have cast doubt on the credibility of endometrial receptivity assays, which play a pivotal role in the successful embryonic implantation. The human endometrium is an amazing structure that goes through changes during the menstrual cycle to create a receptive state for the embryo. This special period, known as the window of implantation (WOI), shows a specific gene expression pattern that indicate its receptivity.

Our endometrial receptivity map, ER Map®, can accurately predict the endometrial receptivity status through transcriptomic analysis. Studies have shown that the use of ER Map® for the precise identification of the WOI and the personalized schedule of embryo transfer can significantly improve pregnancy rates.

En definitiva, el test ER Map® permite identificar el momento óptimo del endometrio para transferir el embrión, es decir, definir exactamente cuándo hay más probabilidades de embarazo.
IGLS Genetic and immunology testing laboratory With a strong bet on innovation, research & development, IGLS top-tier scientists and multidisciplinary teams, pool the best of their expertise and know-how to deliver best-in-class, precise and reliable solutions for assisted reproduction centres, hospitals and healthcare institutions across the world.

What sets ER Map® apart from other tools for studying endometrial receptivity?


ER Map® is a highly optimized tool, specifically designed to target 40 genes that play crucial roles in endometrial receptivity and the immune response. These genes are unique to the endometrium and have been extensively studied for their involvement in the process of endometrial proliferation, receptivity and embryonic implantation.


When it comes to gene expression analysis, ER Map® uses high-throughput RT-qPCR, the most accurate and reliable technique currently available. This validated technique is considered the gold standard for gene expression analyses, avoiding limitations in the ranges of detection, and in background hybridization and probe saturation processes.



ER Map® approach to WOI identification guarantees a personalised determination of the best time for embryo transfer. While other tools determine the optimal implantation stage using a statistical estimation with an associated significant error, ER Map® takes into account the unique characteristics of each patient’s endometrium and confirms each patient receptivity period minimising diagnostic error.



ER Map® has been proven to be highly reproducible, with 100% concordance of results from double analysis of biopsies within the same patient and cycle. Moreover, the improved IVF outcomes in assisted reproduction treatments (ART) after ER Map-guided transfers also demonstrate its reproducibility and reliability.


Successful results

Studies have shown that when ER Map® is used for personalized embryo transfer guidance, pregnancy rates significantly increase. Our data show 35% increment in implantation rates and a 50% reduction in pregnancy loss, guaranteeing the evolution of pregnancy in 80% of the cases.


ER Map® determines with the high accuracy the period of endometrial receptivity which is crucial for maximizing ART and IVF outcomes. A deviation of just 12 hours from the WOI in the embryo transfer schedule can negatively impact the results, highlighting the importance of precise timing.


Wide-Range Indications

ER Map® help patients beyond those experiencing implantation failure can helps patients with recurrent miscarriage, poor responders, infertility of unknown origin or those willing to provide the best uterine environment for their embryos.



Amidst the recent discussions surrounding endometrial receptivity aessays in scientific and medical publications, IGLS would like to emphasize that the overall credibility of endometrial receptivity studies should not be undermined based on findings related to specific tools. It’s important to recognize that while all endometrial studies aim to determine the window of implantation (WOI), different techniques may yield varying results. Considering the characteristics mentioned above, we maintain our belief that ER Map® continues to be a reliable and precise tool for ART professionals.

Endometrial receptivity