What is an Endometrial Receptivity Analysis Cycle (ERA)?

Determine the optimal date in a surrogate’s cycle for embryo transfer.

Endometrial receptivity analysis (ERA) is a diagnostic tool that helps determine the optimal timing for embryo transfer during an in vitro fertilization (IVF) cycle. This procedure may be recommended for women who have experienced recurrent implantation failure or for those who have been unsuccessful with previous IVF cycles. In this article, we will discuss what an ERA cycle is and how it can help improve IVF success rates.

What is Endometrial Receptivity Analysis?

The endometrium is the lining of the uterus that thickens during each menstrual cycle in preparation for a possible pregnancy. Endometrial receptivity is the window of time during which the endometrium is most receptive to an embryo for implantation. An ERA test helps determine the precise timing of this window by analyzing the gene expression patterns of the endometrium.

The ERA cycle involves a biopsy of the endometrium, which is then analyzed to determine the optimal time for embryo transfer. This test can help identify any abnormalities or imbalances in the gene expression patterns of the endometrium, which may be prevent successful implantation.

What are the benefits of an ERA Test?

  • Proponents claim that roughly one third of IVF cycles fail because the transfer was done outside of the optimal window.
  • Claimed increased success rate for IVF cycle.

What are the downsides of an ERA Test?

  • Takes several weeks to perform the test and obtain the results.
  • Procedure is invasive, painful, and expensive.
  • No clear indication that ERA is predictive and useful for IVF patients.  Majority of the studies are sponsored by the companies that create ERA testing products and services.
  • A patient's window of implementation may also change from cycle to cycle and research on predicting these changes is limited.

Should you get an ERA?

ERA testing is relatively new and has not been extensively tested.  However, many companies have commercialized the testing and it is readily available in the marketplace.  

A 2021 randomized trial of ~800 subjects split into two control groups.  Group 1 used traditional implementation timing and group 2 used ERA based implementation timing.  Their conclusion was that there were no differences for single euploid Frozen Blastocyst Transfers.  I.e., the ERA test was not predictive and did not change the success rate.

If you have issues with recurrent implantation failures this may be a test that you want to discuss with your IVF physician.  Talk to your OB/GYN or healthcare provider about whether or not an ERA makes sense for your scenario.

References

# ART IVF
3 Healthy Habits Before an IVF Transfer