What is the Endometrial
Receptivity Test (ERA)?

What is it ?

The endometrial receptivity test is a test by means of which the ideal moment to perform an embryo transfer is sought, which is known as the implantation window. It  is unique in each patient, facilitating the personalization of the embryo transfer in each case. This is of vital importance, since we know that 3 out of 10 patients have a displaced window of implantation.

The endometrium is the tissue (mucosa) that lines the inside of the uterus. It changes during the menstrual cycle and prepares itself for embryo implantation. It will only be “receptive” when it has the thickness and the necessary conditions to promote this dialogue between the embryo and the endometrium, and nesting or adhesion to the maternal endometrium takes place. The endometrium is only receptive for a short period of time, from 12 to 48 hours. But this rule is not always followed: it is crucial to know the details of each patient’s implantation window, as it could be displaced, preventing the success of the treatment. Therefore, it is important to know the implantation window of each patient and, therefore, the ideal moment in order to increase the chances of embryo implantation.

For whom is it?

The endometrial receptivity test is recommended in IVF, Egg Donation, Embryo donation and ROPA method treatments since the transfer should be performed at the moment of maximum receptivity. In addition, it is important to perform in the following cases:

  • History of implantation failure in previous treatments and with good quality embryo transfer.
  • Infertility of unknown origin.
  • Treatments in which a preimplantation genetic diagnosis (PGT) is performed.

In each case, Vida Fertility Institute specialists will do their best to detect the causes of infertility and find the most appropriate solutions for each patient. In some cases the endometrial receptivity test can be combined with the endometrial immunology test to complete the study and increase the chances of embryo implantation.

How is the Endometrial
Receptivity test process?

What does it consist of ?

The endometrial receptivity test is a very simple test that consists of taking a small sample of endometrial tissue after completing an endometrial preparation cycle. The purpose of this test is to reproduce exactly the conditions of an embryo transfer. It is also used to check if the endometrium meets the appropriate conditions for subsequent embryo implantation and to determine the exact moment at which the embryo transfer should be planned.

Endometrial preparation is a simple treatment. It usually consists of taking estrogen and progesterone, through transdermal patches, orally or vaginal ovules. The endometrium is prepared to achieve an adequate thickness and from there the progesterone is started to determine the best time to take the endometrial tissue. It  will be indicative of the ideal time to plan the transfer, depending on the results of the endometrial biopsy.

And after ?

After the biopsy, the sample obtained will be analyzed using massive sequencing technology. It is to  know if the endometrium is receptive or if it needs a different prior preparation. In this way, for the future embryo transfer, we will have to follow the recommendations according to the results obtained. We will personalize the strategy to be followed in each case.