1. What is ERA?
ERA refers to Endometrial Receptivity Array. It is done to check if the lining of the uterus is suitable for embryo implantation and thereby a successful pregnancy.
The genetic material of endometrial cells has a unique expression when it's receptive. In ERA test, an advanced computer algorithm is used to classify a sample as receptive or non- receptive.
2. For whom is it indicated?
ERA is done in couples who have repeated implantation failures. It claims to help women pursuing In Vitro Fertilization (IVF) determine whether their endometrium is receiving an embryo at the right time in an attempt to maximize their chances of a successful pregnancy and live birth.
3. How is it done?
The menstrual cycle of each woman has an implantation window - i.e. a small window of optimal time during which her uterine lining reaches the perfect state for implantation. This window lasts for a few days, typically from the 19th day to the 23rd day of her cycle. While about 80% of women have this window at the expected time, the remaining 20% tend to have a unique window that occurs later or earlier than expected. In IVF treatment, to avoid implantation failure, it's important to find if the window is open or closed before transferring the embryo to the uterus.
ERA test is done by obtaining a sample of endometrial lining during the implantation window. A tiny catheter is inserted through the cervix. Suction is created to draw out a sample of tissue from the lining. This sample is then sent for analysis using Next Generation Sequencing technology. If the tissue happens to be non-receptive, the test has to be re-performed, until the perfect implantation window is found.