Offered the ERA test? We used it in 750+ patients, then stopped.

The ERA test checks whether the womb lining is ready for an embryo on the usual transfer day, by reading genes in a small sample of the lining.

The lining is receptive for only a short window each cycle, called the window of implantation. The idea behind ERA is that this window sits earlier or later in some women, and that moving the transfer to match it helps. Endometrial receptivity array, analysis and assay are three names for the same test.

The ERA test needs a practice cycle: the lining is prepared as for a frozen transfer, and on the day an embryo would go in, a sample of lining is taken instead.

On day 2 of your period a scan checks the lining is thin. Oestrogen tablets build it up over about 7 to 12 days, then progesterone starts. After about 5 days of progesterone, a fine catheter takes the sample in the clinic, without anaesthesia. Most women feel cramping like period pain, not sharp pain.

The transfer happens in a later cycle, usually the next month at the earliest, because the biopsy uses the slot the transfer would have had.

You wait for the report, have a period, and then prepare the lining again. The transfer is timed by the report's advice. In practice the test adds about a month, a procedure and a bill before any embryo goes back.

Because it gives a reason and a plan to couples whose good embryos have failed and who have been given no explanation.

For a doctor sitting opposite that couple, it is hard not to offer something. That is exactly why it needs scrutiny. The couples most drawn to an add-on are the ones least able to weigh it, and a willingness to try anything is not evidence that it works.

In our own patients it did not improve live births enough to keep recommending it, and the published evidence now says the same.

We offered ERA for several years, in more than 750 patients. What decided it was the result set against the cost: an extra cycle, a biopsy and a bill, without a matching gain. Since then, a large double-blind randomised trial (JAMA, 2022) found no difference in live births between ERA-timed and standard-timed transfers. ESHRE's 2023 recommendations say the available receptivity tests are not recommended, and the HFEA rates the test red. This is not a claim that ERA can never help anyone; it is what we saw, and what the evidence found.

We review the whole picture rather than add one test, and use a few add-ons only for the couples they fit.

We revisit the IVF cycle itself: stimulation, embryo quality and transfer technique. Where the cavity is in question, hysteroscopy looks at it directly. For selected women with repeated failure or loss, we may test the lining for harmful bacteria (EMMA/ALICE). Immune testing is kept for a specific subgroup. Embryo testing (PGT) is used in selected cases, discussed with you. Both partners are assessed.