What is the Right Time for an Embryo Transfer?
ERA testing—It is time to pay attention to the uterus
When a patient or couple begins an IVF cycle, we are always hopeful that success will be achieved the very first cycle. Despite excellent pregnancy rates, some patients may require more than one cycle to achieve a healthy pregnancy. Most failed cycles occur because the embryo was genetically abnormal and not healthy enough to develop into a baby. Sometimes other factors play a role, too. For instance, if the uterine lining is not optimized, then it may be more difficult for an embryo to implant. What is the right time for an embryo transfer?
Historically, the timing of embryo transfers was always the same for all patients. We now understand that a “one size fits all approach” may result in embryos being transferred at the wrong time for some women. Each woman has a window of receptivity during which her uterus can allow an embryo to implant. This window is not the same for everyone, and up to 30% of patients may have a window that varies from what we used to consider the norm.
We can measure a woman’s window of receptivity through something called an Endometrial Receptivity Analysis (ERA). Her uterus is exposed to estrogen and progesterone in a mock cycle. We then perform an endometrial biopsy on the day she would have otherwise had an embryo transferred. The biopsy is performed with a very small pipelle (tiny plastic tube) that is inserted through the cervix and into the uterus. A small sample of endometrial tissue is obtained. The endometrial tissue is then sent off for a molecular analysis to determine that woman’s individual window for implantation. The results are then used to dictate the timing of any subsequent embryo transfers.
All fertility patients are potential candidates for ERA testing. In particular, women who have had multiple failed IVF cycles, despite seemingly good quality embryos, may benefit from ERA testing. Similarly, women with multiple chemical pregnancies or early miscarriages from IVF may benefit from ERA testing. Factors such as body mass index and age may also influence a woman’s window of receptivity.
We are very proud of our pregnancy rates at Fertility Centers of New England. If you are interested in seeing if you would be a good candidate for ERA testing or have further questions about the best treatment path for you, please contact us today!