ERA test is one of the methods that significantly increase the possibility of pregnancy. Most of the negative results that may be encountered in IVF treatments are caused by egg, sperm, or embryo. The implantation failure is associated not only with the quality of the embryo but also with the endometrial receptivity. The uterine environment and the receptivity of the uterine lining where the embryo will attach and get nourishment are as important as the quality of the embryo to be transferred. A thick, receptive, nourishing uterine lining is the best possible environment for the embryo. ERA test plays a crucial role in the preparation of this environment.

In the routine evaluations carried out by clinics during the treatment process, the uterine environment is generally examined by hysteroscopy or ultrasonography. During these examinations, some uterine pathologies such as polyps, fibroids, septate uterine, and adhesions that may interfere with fertility by preventing the embryo from implanting can be detected and corrected surgically. If there is no genetic reason or uterine pathology causing implantation failure, testing is required on the receptivity issues with the uterus. At this point, it is essential to determine how healthy the cellular microenvironment is to enable the embryo to attach or whether it is ready for the embryo implant. However, it is not possible to test the receptivity of the uterine lining with the applications used to examine and correct uterine pathologies mentioned above.

In recent studies, the following conditions have been observed in some couples who failed to achieve pregnancy despite two or more trials and quality embryo transfer:

• Uterine tissue does not develop synchronously with embryo development.
• When the embryo is ready for pregnancy, the uterine tissue does not reach sufficient maturity for the embryo to attach.

In such cases ERA test comes into play. The ERA test enables the identification of the period when the uterine tissue can reach the most suitable stage for the embryo attachment before IVF treatment. Once this period is identified the most accurate timing for embryo transfer is determined. This promotes successful embryo implantation and in turn, a successful pregnancy in women undertaking IVF treatment.

The Benefit of ERA Test in Donation Treatments
Since eggs and sperm with high pregnancy potential are used in donation treatments, the success of the IVF treatment depends mostly on the capacity of the uterine tissue to accept the embryo, rather than the egg, sperm, and embryo. The results obtained after the ERA test show that the success of pregnancy, especially in some patients, can be increased even more by determining the treatment program and embryo transfer day accurately, or moving the date of embryo transfer when necessary. Considering the ERA test results, it is possible to understand the reasons for the failed IVF treatments in the past despite transferring the embryos with high pregnancy potential. Therefore, the ERA test offers new hopes to patients struggling with recurrent implantation failure.

How is the ERA test performed?
The menstrual cycle of each woman has an optimal time during which her uterine lining reaches the perfect state for embryo implantation. Through the ERA test, the intrauterine membrane of the patient is followed within a certain program with the onset of menstruation. Then, a tiny endometrial tissue is taken with a biopsy on a specific day scheduled by the doctor. Although tissue removal is a very simple procedure, it is performed in the operating room and generally by administrating mild sedatives for the comfort of the patient. Then, the tissue sample is sent to the lab and over 360 gene expressions are analyzed in detail by using advanced genetic diagnosis methods. Within about 4 weeks, the results are evaluated and consequently, it is determined whether or not the uterine tissue is receptive for embryo attachment. Based on the ERA test results, the date of personalized embryo transfer is determined.

Important Issues to Know About ERA Test:
It is extremely important to plan the test and treatment by taking frozen embryo transfer applications as a basis to enable the prospective couples to gain maximum benefit from the ERA test.

In other words, the ERA test is not an appropriate test for treatments based on the applications regarding transferring fresh embryos obtained from eggs retrieved after hormonal stimulation of the ovaries.

In order not to limit the benefits that the ERA test provides for couples, the clinic, which is considered for the test, should be able to achieve high success in frozen embryo transfers and procedures as well.