What is an ERA?
A failed transfer can be incredibly disappointing and confusing. News that the transfer did not result in a pregnancy is difficult to understand, especially when your surrogate’s progress looked great, the embryos looked great, and the transfer went off without a hitch. The truth is, there is still an element of luck in IVF pregnancies, and sometimes transfers just don’t work.
Science is getting closer to being able to understand why transfers may be failing while other succeed, and looking for ways to prevent future transfers from continuing to be unsuccessful. In the result of a failed transfer, especially one in which everything looked ideal at the onset, some doctors may ask your surrogate to undergo a new type of evaluation called an Endometrial Receptivity Analysis, or ERA.
The ERA, a practice introduced in 2009 and boasting more than a decade of research, includes a minimally invasive biopsy, taken by a doctor in a consultation room, at a designated point in the menstrual cycle. The day the biopsy is taken will differ based on the medical protocol the woman is on, and is used to study more than two hundred genes to identify the optimal time in her cycle to perform an embryo transfer.
The analysis considers genetic and molecular factors and highlights the days that the uterus is receptive to embryo implantation as well as the days where the uterus is not at all receptive to a potential implantation, thus making pregnancy highly unlikely.
This new process is similar to a “mock cycle,” or a cycle in which a surrogate takes all IVF medications without the intention of an embryo transfer at the end. The goal of a mock cycle is to monitor a surrogate’s response to medication in order to determine the ideal time in a woman’s medical cycle to complete the embryo transfer. While the start of the process looks very similar, the way these two cycles end is what sets the ERA apart from a mock cycle.
At the end of the ERA, the doctor will present the surrogate with a PET, or a Personalized Embryo Transfer window. Consider this cycle as a way to find the best and most “personalized” window for success. A mock cycle does not provide this level of personalized insight into the most optimal time to transfer an embryo into an individual woman. Instead, it offers an in depth look at only how the surrogate’s body responds to the medication.
In general, surrogates will not be asked to complete an ERA prior to a transfer. Currently these tests are primarily being used for surrogates who have experienced at least one failed transfer.
For more information on ERA and how they work, please follow this link. https://www.igenomix.com/fertility-challenges/what-to-know-about-endometrial-receptivity-analysis/