ERA Test: What It Is and Who Needs One?

According to Dr. Hrishikesh Pai, best infertility doctor in India, “Zero sperm in the ejaculate isn’t the same as zero sperm production, and that distinction changes the entire treatment plan.”

The test looks at gene activity in the uterine lining to pinpoint the exact window when it’s most receptive to an embryo.

Biopsy: A small tissue sample is taken from the endometrium during a mock cycle timed to match a real transfer’s hormone schedule.

Gene Panel: The sample is analysed for the expression of over 200 genes linked to endometrial receptivity, using that pattern to classify the lining as receptive or not.

Personalised Window: If the lining tests non-receptive at the standard time, the result suggests shifting progesterone exposure earlier or later before the next transfer.

Mock Cycle: Because the biopsy happens in a cycle without an actual embryo transfer, the result guides timing for a future frozen cycle rather than the one it’s taken in.

That adjusted timing gets applied directly to a subsequent frozen embryo transfer, which is why the test only makes sense alongside a freeze-all or FET approach.

Not every IVF patient benefits from this test, and using it outside the right situation adds cost without much evidence of a real gain.

Repeated Failure: Women with two or more failed transfers using good-quality, chromosomally normal blastocysts are the group most often offered this test.

Randomized Trial Evidence: Two major randomized trials found no significant live birth difference between ERA-guided and standard-timed transfers, and one large study even linked personalised timing to lower outcomes in donor and autologous cycles.

Not First-Timers: Studies looking specifically at first-time transfers found no live birth benefit from routine ERA testing, and that’s exactly why it isn’t offered as a default add-on.

Alongside Other Testing: ERA often gets ordered together with immunology or PGT-A results, since timing is only one of several possible reasons a good embryo doesn’t implant.

Where ERA fits among the other tests used for unexplained failure is covered in more depth in Recurring IVF Failure

Dr. Hrishikesh Pai is MD, FRCOG (UK-Hon), MSc, FCPS and FICOG, with over 40 years of experience in obstetrics, gynecology and infertility. He’s the Founder and Director of the Bloom IVF Group, which has completed more than 25,000 IVF cycles across eight centres and works through recurrent implantation failure case by case rather than defaulting to the same add-on for everyone.

Couples sometimes ask for ERA testing simply because they’ve read about it online, and that’s not always the right next step. What matters more is figuring out why the last transfer actually failed before ordering another test.

References

1. Endometrial Receptivity Analysis (ERA) test: an unproven technology NCBI: 
2. Use of the endometrial receptivity array to guide personalized embryo transfer after a failed transfer attempt PubMed: