Today, a prominent East Coast doctor discussed the value of the Endometrial Receptivity Assay (ERA). This test is performed on an endometrial biopsy, timed to ovulation, or taking progesterone in a mock cycle. In theory, there is a small window of time that the endometrium (lining) is open to implantation. The ERA determines varying the days of progesterone before an embryo transfer will improve the implantation rate. An “abnormal” result is not alarming. It just tells us how to adjust the protocol for a frozen embryo transfer. Unlike other older endometrial biopsy tests, this is the only one that provides a solution. If a woman has an abnormal result, she is better off having a frozen transfer than a fresh one.
According to the original authors, 20% of infertile women have an abnormal result. I have been offering this test for over 2 years and agree with that estimate. When we alter the protocol as suggested by the test, we see many pregnancies. While this test is not yet accepted as a routine step for all patients, I recommend it for women who have one failed IVF cycle with PGS normal embryos, and women with long-standing unexplained infertility.
The ERA biopsy and other tests for implantation failure are discussed on my website: