Endometrial Scratching: What the 1,364-Woman Trial Found

Probably not, and certainly not by much. The largest trial found exactly the same live birth rate with and without it, and the 2026 Cochrane review, pooling the most reliable trials, concluded the effect is unclear: it could be nothing, or a small gain of up to about 5 percentage points.

No guideline we found recommends it. The UK regulator, the HFEA, rates it amber for most IVF patients (conflicting evidence) and grey for people with repeated failed transfers (not enough good evidence). ESHRE, the European society, does not recommend it for routine use.

After a failed transfer, a quick procedure that promises to make the lining "more receptive" is easy to say yes to. That is exactly when it helps to know what it has and has not been shown to do.

A deliberate small injury to the lining of the womb (the endometrium) before an IVF cycle. A thin plastic tube, called a pipelle, is passed through the cervix into the womb and moved to scrape the lining — in the UK trial, rotated and withdrawn three or four times. It is usually done in the second half of the cycle before embryo transfer; the Lensen trial allowed it any time from day 3 of the preceding cycle to day 3 of the transfer cycle.

The idea, as the HFEA describes it, is that the body's repair response releases chemicals and hormones that make the lining more receptive to an embryo. Several small early studies suggested a benefit; the large trials below did not. It is sometimes done during a hysteroscopy rather than with a pipelle alone.

Two large trials, both negative:

• Lensen 2019 (NEJM). 1,364 women having IVF with fresh or frozen embryos, in New Zealand, the UK, Sweden, Belgium and Australia. Live birth 26.1% in both groups.
• Endometrial Scratch Trial 2022 (UK, NIHR). 1,048 women aged 18 to 37 having their first IVF cycle. Live birth 38.6% with scratching against 37.1% without — a 1.5-point difference that was not significant. Pooled with eight earlier trials in first-cycle patients, the odds ratio was 1.03. The authors recommended that it not be done before a first cycle.

The 2026 Cochrane review is the widest view. It found 24 trials of 7,234 women, but many were at high risk of bias, so its main analysis used only the eight most reliable (4,402 women). Live birth odds ratio: 1.12, with a 95% confidence interval of 0.98 to 1.28. In plain terms, if 27 in 100 women would have a baby without scratching, between 27 and 32 would with it. The authors called the effect unclear, and said their conclusion had not changed since 2021.

Carefully in both directions. A small trial that finds no difference settles little, because its range of plausible effects is wide. A large trial with a narrow range rules out big effects. The Lensen trial is the second kind: its interval rules out large gains.

What it cannot do is rule out a modest benefit. An upper limit of 1.27 on a 26% baseline still allows a gain of a few percentage points, and the pooled Cochrane estimate leans slightly positive. So the honest reading is not "proven useless" but "no benefit shown, and any benefit is small". That fits the HFEA's amber rating, which means conflicting evidence, not proven to have no effect.

This is the group it was most often offered to, and the evidence is weaker here, not stronger. The HFEA rates it grey for recurrent implantation failure because no moderate or high-quality study has explicitly tested it in these patients. ESHRE's 2023 recommendations on recurrent implantation failure state plainly: "Intentional endometrial injury is not recommended."

Subgroup analyses have not found a group that benefits. ESHRE's 2023 add-ons review describes one meta-analysis in which women with at least one failed cycle appeared to gain (risk ratio 1.18), but the effect was not significant in women with two or more failures (risk ratio 1.30, 95% CI 0.87 to 1.94). Another review found no difference whether women had no, one, or two or more failed cycles.

Even so, practice has not caught up. In the clinician survey ESHRE relied on, 57% of the clinicians who completed it said they offer endometrial injury for recurrent implantation failure. ESHRE describes most such interventions as applied empirically, driven by a perceived need to act.

It is usually uncomfortable rather than severe, but it varies a lot. In the Lensen trial the median pain score was 3.5 out of 10, with a quarter of women scoring 6 or more. The Cochrane review concluded it probably causes mild to moderate pain.

• Some bleeding can occur (HFEA; ESHRE).
• Infection is uncommon, but an existing cervical infection could be carried into the womb (HFEA). ESHRE notes a small infection risk when it is done by hysteroscopy.
• No extra known risk to a baby born after treatment (HFEA).
• Miscarriage: no clear difference (Cochrane 2026, odds ratio 1.00, low-certainty evidence).

We could not find a verifiable Indian price for scratching, so we do not quote one. Ask for it as a separate line on the quote. Under the ART Act 2021 (section 21), clinics in India must explain the advantages, disadvantages, cost, side effects and risks of each procedure.

1. Why is it recommended for me specifically, and what did the largest trial find for live birth?
2. Is this my first cycle? (The UK first-cycle trial recommended against it.)
3. If it is for failed transfers: what has been checked about the embryos and the womb before adding a procedure?
4. What does it cost, and how would my plan change if I declined it?

None of this means a clinic offering it is acting in bad faith. Practice changes slowly, and a doctor who saw apparent benefit years ago may still believe in it. But the answer to the first question tells you how the clinic weighs evidence generally. For the wider picture, see our review of IVF add-ons and what is worth investigating after a failed cycle.