How Is an Endometrial Receptivity Test Performed?

The ERA test (Endometrial Receptivity Analysis) is a molecular diagnostic test that assesses the receptivity status of the endometrium. Its goal is to identify the optimal moment in the menstrual cycle to perform embryo transfer and adjusting the transfer day in in vitro fertilization (IVF) treatments.

What is the ERA Test for? 

The main purpose of the ERA Test is to personalize the embryo transfer day for each patient. This is especially useful for patients who, despite having good-quality embryos, have experienced repeated implantation failures.

How is the ERA Test Performed? 

The ERA Test should be performed at the moment the implantation window theoretically begins. In a natural cycle, this window usually starts around day 21, although normal cycle length variations must be taken into account. In an IVF treatment cycle, this window begins 5 days after having started progesterone administration.

To carry it out, an endometrial biopsy must be performed by using a special cannula inserted without anesthesia through the cervix. An endometrium sample from the uterine fundus is then collected. Once the tissue has been obtained, it is placed in a suitable sterile container and kept at low temperatures until processing.

Is it Painful? 

Endometrial biopsy is a quick and minimally invasive procedure. It may cause mild discomfort similar to menstrual cramps.

When Should an ERA Test Be Performed? 

It is recommended in the following cases:

• Patients with previous implantation failures in IVF treatments but with good-quality embryos.
• Patients who have experienced repeated miscarriages with no apparent cause.