What is ERA and why it is done?

What is ERA and why it is done?

The amount of emotional stress and anxiety that a couple goes through while undergoing an IVF treatment is inexplicable. No couple wants to go through the dilemma of a repeated implantation failure or RIF. Modern technologies such as ERA offer a new hope to the couples coping with implantation failure.

What is ERA?

In the field of fertility treatment, the term ERA stands for Endometrial Receptivity Array or Endometrial Receptivity Analysis. It is a genetic test in which a small sample of a woman's endometrial tissue is taken to assess if her endometrial lining is properly developed such that it can successfully accept an implanting embryo.


ERA, which is done using the latest scientific technology, analyses the expression of 236 genes per sample with the objective of determining the optimal time window for planting the embryo into a woman's uterus. This promotes a successful embryo implantation and in turn, a successful pregnancy in women undertaking infertility treatments.

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 Process?

Before discussing how ERA is done, let's take a look at the how ERA test works. The genetic material of endometrial cells has a unique expression when it's receptive. Here, an advanced computer algorithm is used to classify a sample as receptive or non- receptive.

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.