Endometrial Receptivity Analysis (ERA)

ERA, or Endometrial Receptivity Analysis, is a test to determine the receptivity of the endometrium.

ERA may increase the chance of pregnancy by predicting the ideal time for the implantation of the embryo during an IVF cycle.

A biopsy of endometrial tissue is taken and analyzed. Results will indicate whether the endometrium was receptive or non-receptive at the time the biopsy was taken.


receptive result indicates the endometrium is likely to be receptive and the embryo is likely capable of implanting into the uterus relative to the day the biopsy was taken.


non-receptive result indicates that the endometrium is either pre- or post-receptive relative to the day that the biopsy was taken. The embryo transfer would not be recommended.

non-receptive result means the endometrium is either pre-receptive or post-receptive.

In this case, a new window of implantation will be suggested and a second biopsy and test are recommended to confirm the new personalized window of implantation.

ERA links to a major improvement of the global pregnancy rate, up to 85%* in those personalized transfers made according to the test results.

* SREI Prize Paper. O-115 Simón et al. on behalf of the ERA RCT Consortium. Prospective, randomized study of the Endometrial Receptivity Analysis (ERA) test in the infertility work-up to guide personalized embryo transfer versus fresh transfer or deferred embryo transfer.


In an IVF treatment, the focus is often on the quality of the embryos, looking for those which are more likely to lead to a successful pregnancy after transferring them to the uterus.

But in this process, the function of the endometrium, the lining of the uterus which houses the embryo allowing for its implantation, is equally important.

Synchrony combines our PGT-A and ERA tests to select the best embryo and transfer it to the uterus at the right time.