Endometrial Receptivity Analysis (ERA)

ERA is a test that helps us determine the optimal time for embryo transfer, increasing the chances of successful implantation and pregnancy. The endometrium (womb lining) is only receptive to embryo implantation for a short period, known as the implantation window.

What is the ‘implantation window’? The implantation window is a specific time during the menstrual or treatment cycle when the uterine lining is ready to support embryo implantation. This window typically occurs around 7-9 days after ovulation or after fertility treatment that simulates ovulation. However, the timing of this window can vary between individuals, and the lining may not be receptive outside of this window, reducing the chances of successful implantation.

What does ERA involve? ERA can be performed during either a natural menstrual cycle or a stimulated cycle. The procedure is similar to a smear test, where we take a biopsy of the uterine lining and analyze 248 genes related to the timing of the implantation window. The test results will indicate the most receptive time for embryo transfer, helping us optimize the timing of your procedure for the best chance of success. The results are typically available within 2-4 weeks, so we can plan your next embryo transfer accordingly. If an unusual implantation window is found, embryos will be frozen for a later transfer in a frozen embryo transfer cycle.

Could ERA be right for me? ERA is often recommended if you are under 37 and have had unsuccessful embryo transfers, particularly with good-quality day five embryos. It may also be helpful if you have limited opportunities for future treatments, such as when:

• You have only one embryo available for transfer
• You are using donated gametes, and future embryo availability is uncertain

Are there any risks? The endometrial biopsy used in ERA testing is a low-risk procedure commonly performed in gynecology. While mild cramping is common after the procedure, there is a small risk of bleeding, infection, or uterine perforation