Any subject stops being difficult when it is presented in a clear and comprehensible way. In this webinar, two fertility experts from ISIDA IVF
: Svetlana Shiyanova (Chief Doctor from the Infertility Treatment Center) and Inna Moroz (Fertility Specialist) accepted the challenge and explain step by step some of the most complicated issues of IVF treatment processes: endometrial receptivity, endometrial scratching and implantation window. All in all we think they did an excellent job!
What is endometrial receptivity?
Inna started with presenting the four stages of embryo implantation: orientation, apposition, attachment and invasion. She explained that the endometrium, the inner lining of the uterus, has to be in a perfect condition for the embryo to successfully complete all the implantation stages and begin developing into a fetus. However, the condition of the endometrium is not always ideal for embryo implantation and this can be the cause of Recurring Implantation Failures (RIF).
Obviously, the quality of the embryo is key. Even if the endometrium is in perfect condition, the attachment and invasion stages will not take place if the embryo quality is low (when it has genetic abnormalities for instance). Only the successful interaction between these two guarantees the best outcome of the implantation process.
According to Inna, evaluating the condition of the endometrium before the embryo transfer is very important. Hormones such as estrogens and progesterone stimulate growth and development of the endometrium during a woman’s menstrual cycle. Changes in hormone levels affect the endometrium thickness and the number of glands and vessels on the surface of the uterus wall. This in result impacts the receptivity of endometrium during implementation stages. If the thickness of endometrium is less than 7 mm, it is not in a good condition to accept the embryo. Only when it reaches 8 mm and more, can the doctors proceed with next stages of implantation process.
nna highlights that the endometrium has a very difficult constitution and it has to be evaluated with different markers and factors such as immune cells, signalling factors, nutrients and physical environment. It all can be helpful in determining any form of potential endometritis. The endometrial evaluation can also be based on gene expression analysis – this is another way of checking if the endometrium is ready to accept an embryo of great quality.
What is the window of implantation?
Inna explains that the window of implantation is the time when a woman’s endometrium is most receptive and ready to accept your embryo. If you have the regular cycle of 28 days with a possible ovulation around the 14th day, the best day for embryo transfer will be from 19th to 21st day of the cycle.
There are a lot of genes to be expressed at different stages of the menstrual cycle. As the window of implantation can be displaced, it is necessary to conduct the analysis of endometrial receptivity genes. By using the real time PCR method, more than 400 genes that can be expressed and evaluated. Inna says that in order to determine the correct window of implantation for a patient, they need the so-called ‘REpoint’ test for endometrium receptiveness genes.
How to evaluate the result of the ‘REpoint’ test?
According to Inna, the results of the ‘REpoint’ test can be very useful in creating an individual treatment plan for a patient. If the test determines that the endometrium is pre-receptive, it means that the embryo transfer has to be postponed for a couple of days. It is also necessary to increase the number of days of progesterone supplementation.
If the test shows a receptive result, it means it is the right day for the implantation and embryo transfer. Consequently, if there is a post-receptive endometrium result, the embryo transfer has to happen a little bit earlier and the number of progesterone supplementation days has to be cut down.
Why is it important to use the ‘REpoint’ test?
Inna and Svetlana highlight that up to 25% of population has a displaced window of implementation. Identifying the ideal window requires the analysis of the endometrial receptivity genes. Without the proper testing, it is easy to decrease the chances for successful embryo implantation.
Inna and Svetlana also present three most important cases when REpoint test is used in their clinic. These are the following:
- RPF (recurring pregnancy failures)
- Embryo transfer after pre-implantation genetic testing
- Suspecting a change in the implantation window after miscarriage
The last subject Inna and Svetlana dealt with during their webinar presentation was a technique called endometrial scratching. A biopsy is applied to the endometrium to create an injury or tissue irritation. According to Inna, this technique should lead to the process of tissue regeneration and, as a result, to the improvement of endometrial receptivity.
Although there is no conclusive research which proves the effectiveness of endometrial scratching the technique is used when the doctors suspect that there are some immunological factors behind the woman’s infertility. Of course any decision has to be proceeded by a careful and detailed evaluation of a patient’s individual case and her endometrium immunological issues.