The receptive endometrium is the one that is prepared for the implantation of the embryo. This period of receptivity is called the window of implantation, or WOI.
In a 28-day menstrual cycle, the implantation window occurs between days 20-24 of the cycle.
It is important to know that each woman has a unique window: some occur earlier than “normal”, others last longer than others, and so on. It is estimated that 3 out of 10 women have a displaced implantation window, from the global casuistry of Igenomix, it is known that approximately 50% of women require an adjustment in the hours of progesterone to carry out the transfer at the ideal time.
Knowing the implantation window, the chances of pregnancy can be optimized through a personalized embryo transfer.
What is the Window of Implantation?
A window of implantation is the span of a few days in which your endometrium lining (which is essentially the lining of your uterus) is at its most optimal state to receive an embryo for implantation. An embryo needs to implant in order to grow and develop, which is necessary for you to sustain a successful pregnancy. Coordinating this period of time between the window of implantation and the development of an embryo can be key in a successful IVF outcome. Since every patient’s window of implantation can vary, this test can pinpoint the best timing of not just any embryo transfer, but one that’s personalized to when your endometrial lining is most receptive.
How Do I Find Out My Implantation Window?
You can find out your implantation window by speaking to your doctor and asking about implantation testing. There is something called Endometrial Receptivity Analysis (ERA), developed by Igenomix, that can determine your personalized implantation window.
An endometrial biopsy will be taken by your doctor in a mock embryo transfer cycle, which entails taking a small sample of your endometrial lining. This sample would then be carefully analyzed to determine when your specific window of implantation would be.
With these results, your doctor will know the ideal time to transfer the embryo to give it the best chance of implanting in the uterus, thus giving you the best chances of achieving a pregnancy.
Who Should Consider Implantation Testing?
If you have undergone several IVF cycles that were not successful, where the embryos were of good quality, you might want to speak to your doctor about whether or not he or she feels determining your implantation window would be helpful on your next cycle.
Another factor to consider is if you have had two miscarriages or more and you have never explored genetic testing previously, ask your reproductive endocrinologist about Preimplantation Genetic Testing for Aneuploidy (PGT-A, formerly known as PGS). PGT-A can increase the chances of having a healthy baby and decrease your chances of a miscarriage.
Not only are these indications important to take into account, any other IVF patient, even if they do not have those characteristics, can have an advantage from the ERA test at their the first IVF attempt.