Endometrial Scratching Before IVF: Why It Is No Longer a Routine Add-On

Key Takeaways

Endometrial scratching means making a small, deliberate injury to the lining of the uterus before an IVF cycle, in the hope of helping implantation. The 2026 Cochrane update found that its effect on live birth is unclear: the results are consistent with an increase, no effect or a small reduction. ESHRE does not recommend it routinely or for recurrent implantation failure, and there is no reliable evidence that it helps before a frozen embryo transfer.

Key evidence: Cochrane review update: endometrial injury in IVF (2026) · ESHRE good practice recommendations on add-ons (2023) · ESHRE good practice recommendations on recurrent implantation failure (2023)

On this page

• Endometrial Scratching in IVF
• What the Procedure Is
• Why the Idea Became Popular
• What the Evidence Shows Now
• Before a Frozen Embryo Transfer
• After Recurrent Implantation Failure
• Timing Matters
• Pain and Risks
• What ESHRE and the HFEA Say
• Frequently Asked Questions for Dr. Aksoy
• Sources

Endometrial Scratching in IVF

Endometrial scratching, also called endometrial injury, once looked like a simple way to help an embryo implant. It was a small procedure with a plausible theory behind it, and it offered hope for the next transfer.

Better studies have since changed the picture. The 2026 Cochrane update found that the effect of scratching on live birth is unclear.[1] ESHRE does not recommend it for routine clinical use[6] or for recurrent implantation failure.[7]

Dr. Aksoy’s Approach: I do not use endometrial scratching as a routine step before IVF or after a fixed number of failed transfers. A failed transfer deserves a review of the embryo, uterine cavity, transfer conditions, and—when relevant—the timing and duration of progesterone exposure. It does not automatically create an indication for another invasive procedure.

(Note: This video was recorded in French. English and Arabic audio tracks are available in the YouTube player settings.)

What the Procedure Is

A thin plastic tube is passed through the cervix into the uterus to make a small injury, a “scratch”, to the lining.[1] In most trials this was done with a Pipelle biopsy catheter in the luteal phase (second half) of the cycle before the IVF cycle.[1]

It is short, but it is still invasive.

Why the Idea Became Popular

The theory was that a small injury triggers a local repair response that makes the lining more receptive. The proposed mechanisms include a wound-healing and inflammatory response, decidualisation, changes in gene expression, and better synchrony between the embryo and the endometrium.[6] Decidualisation is the change the lining goes through to prepare for pregnancy.

These ideas are biologically interesting. A plausible mechanism is not proof of benefit; only trials can show that.

What the Evidence Shows Now

The 2026 Cochrane update included 24 randomised trials with 7,234 women. Because many trials were at high risk of bias, its main analysis used only the 8 trials at low risk of bias, with 4,402 women.[1]

The Cochrane authors conclude that the results are consistent with an increase, no effect or a small reduction in the chance of a live birth.[1]

The largest single trial points the same way. In a 2019 multicentre trial of 1,364 women, the live birth rate was 26.1% with scratching and 26.1% without (adjusted OR 1.00; 95% CI 0.78 to 1.27).[2] A UK trial of 1,048 women having their first IVF cycle found live birth rates of 38.6% with scratching and 37.1% without. The difference could be due to chance, and the authors advise against scratching in this group.[3]

Not every analysis agrees. A 2023 meta-analysis that pooled individual participant data from 4,112 women in 13 trials found a possible small improvement in live birth (OR 1.29; 95% CI 1.02 to 1.64). Its authors still advise that scratching be used with caution and that patients be told how uncertain the evidence is.[4] A 2026 meta-analysis of 8 trials also reported a small benefit; for live birth, from 6 trials, the risk ratio (RR) was 1.12 (95% CI 1.03 to 1.22).[13] It pools far fewer trials than the Cochrane update, which remains cautious.[1]

In practice, if scratching helps at all, the effect is small and not reliable enough to justify routine use.

Before a Frozen Embryo Transfer

There is no reliable evidence that scratching before a frozen embryo transfer improves the live birth rate.[5][8]

Few trials have tested this. In a small double-blind randomised trial of women having a natural-cycle frozen transfer, there was no significant difference in clinical pregnancy, ongoing pregnancy or live birth.[5] Because it involved natural cycles only, it does not settle the question for hormone-prepared (programmed) cycles; the evidence is too limited either way. A meta-analysis of first transfers found no difference in the effect of scratching between fresh and frozen transfers, although that does not prove the effect is the same.[8]

After Recurrent Implantation Failure

This is when scratching is most often suggested. After another negative test, it is natural to look for one more thing to try.

Evidence specifically for well-defined recurrent implantation failure remains insufficient, and the available studies have not shown a reliable benefit for live birth.[7][12] In the three small trials in this group summarised by ESHRE, there was no significant increase in pregnancy or live birth, and ESHRE does not recommend it.[7] The HFEA found no moderate- or high-quality studies that looked specifically at recurrent implantation failure.[12] The closest large trial included 933 women after only one failed IVF cycle. In the groups analysed, 110 of 465 women had a live birth with scratching, compared with 88 of 461 without (RR 1.24; 95% CI 0.96 to 1.59). The authors advise against its use outside clinical trials.[9] An analysis that grouped trials by the number of previous failures could not show which patients, if any, benefit.[10]

Timing Matters

When scratching was studied, it was usually done in the cycle before treatment.[1] In some studies, scratching during the treatment cycle itself was linked to lower pregnancy rates or more miscarriages.[8][11]

• In the first-transfer meta-analysis, scratching on the day of egg collection with a rigid Novak curette was linked to a lower combined ongoing pregnancy or live birth rate (RR 0.31; 95% CI 0.14 to 0.69). This was a subgroup result, and because the device also differed, timing and instrument cannot be separated.[8]
• A trial of follicular-phase scratching in the treatment cycle stopped early, after 200 of a planned 360 women. Clinical miscarriage was more frequent with scratching (25% versus 8%). The authors note that, because the trial stopped early, no definite conclusions can be drawn.[11]

These findings do not show that every timing or technique causes harm, but they are another reason not to use the procedure routinely.

Pain and Risks

Scratching probably causes mild to moderate pain.[1] In the 2019 multicentre trial, the median pain score was 3.5 out of 10, and one in four women rated it 6 or more.[2]

ESHRE notes that minimal to moderate bleeding and pain may occur, and that when the procedure is performed by hysteroscopy, there is a small risk of infection.[6] The HFEA says infection after scratching is uncommon, although there is a small risk if the cervix is already infected. It adds that scratching carries no known additional risks for the child.[12]

When the benefit is uncertain, even a minor procedure needs a clear reason to justify its discomfort and cost.

What ESHRE and the HFEA Say

• ESHRE add-ons (2023): “Endometrial scratching is currently not recommended for routine clinical use.”[6]
• ESHRE recurrent implantation failure (2023): “Intentional endometrial injury is not recommended.”[7]
• HFEA (2023): The UK fertility regulator rates endometrial scratching amber for most patients having IVF or ICSI: it is not clear whether it works. For recurrent implantation failure it is grey: there is not enough good-quality evidence to rate it. Its expert committee reviewed the evidence in July 2023.[12]

Related Reading

• Preparing the Endometrium for Frozen Embryo Transfer: HRT, Natural, and Hybrid Cycles
• Fresh vs Frozen Embryo Transfer: Which Fits Your IVF Cycle?
• EmbryoGlue in IVF: What the Evidence Shows and When It Is Not Needed
• After Embryo Transfer: Practical Guidance for the Two-Week Wait

Frequently Asked Questions for Dr. Aksoy

Should endometrial scratching be done before a frozen embryo transfer?

I do not routinely recommend endometrial scratching before a frozen embryo transfer. In this procedure, a thin catheter is used to create a small injury in the lining of the uterus. The aim is that the biological response during healing makes it easier for the embryo to attach. However, the clinical benefit this theory predicts has not yet been adequately shown. In particular, we have no reliable evidence that it increases the live birth rate in frozen embryo transfers. For this reason, I do not consider it necessary to intervene inside the uterus solely to increase the chance of pregnancy. For me, the characteristics of the embryo, the condition of the uterine cavity and correct planning of the transfer timing are higher priorities.

Does endometrial scratching have a proven benefit, and do you use it after recurrent implantation failure?

Conflicting results have been published on this for years. Some studies reported a benefit, but larger, better-designed studies could not show the same result. The Cochrane review updated in 2026 also shows that the effect on live birth is still unclear. In a patient with repeated transfer failure, before turning to scratching, I look for a finding that could explain why the embryo did not implant. I re-evaluate issues such as the chromosomal status of the embryo, pathology inside the uterus, the preparation of the endometrium and the timing of progesterone. If needed, I may perform a diagnostic hysteroscopy, but this is not the same as scratching. At present, I do not regard scratching as a standard treatment for recurrent implantation failure.

Is endometrial scratching painful, and what are its harms and risks?

The procedure can usually be done in the clinic without anaesthesia. A thin catheter is passed into the uterus to create a controlled injury in the endometrium. Most patients feel brief pain or cramping similar to period pain. There may be light spotting afterwards. Complications such as infection are rare, but the procedure is not completely risk-free. In particular, it should not be done in patients with an active genital infection. For me, the real question is whether it is necessary to accept pain, possible complications and extra cost for a procedure whose benefit has not been proven in most patients. That is why I do not think routine use is right.

Sources

1. Perera AK, Gan J, Afroz A, Armstrong S, Raine-Fenning N, Martins WP, Lensen SF. Endometrial injury in women undergoing in vitro fertilisation (IVF). Cochrane Database Syst Rev 2026;5:CD009517.
2. Lensen S, Osavlyuk D, Armstrong S, et al. A randomized trial of endometrial scratching before in vitro fertilization. N Engl J Med 2019;380(4):325–334.
3. Metwally M, Chatters R, Pye C, et al. Endometrial scratch to increase live birth rates in women undergoing first-time in vitro fertilisation: RCT and systematic review. Health Technol Assess 2022;26(10):1–212.
4. van Hoogenhuijze NE, Lahoz Casarramona G, Lensen S, et al. Endometrial scratching in women undergoing IVF/ICSI: an individual participant data meta-analysis. Hum Reprod Update 2023;29(6):721–740.
5. Mak JSM, Chung CHS, Chung JPW, et al. The effect of endometrial scratch on natural-cycle cryopreserved embryo transfer outcomes: a randomized controlled study. Reprod Biomed Online 2017;35(1):28–36.
6. ESHRE Add-ons working group; Lundin K, Bentzen JG, Bozdag G, et al. Good practice recommendations on add-ons in reproductive medicine. Hum Reprod 2023;38(11):2062–2104.
7. ESHRE Working Group on Recurrent Implantation Failure; Cimadomo D, de los Santos MJ, Griesinger G, et al. ESHRE good practice recommendations on recurrent implantation failure. Hum Reprod Open 2023;2023(3):hoad023.
8. Vitagliano A, Andrisani A, Alviggi C, et al. Endometrial scratching for infertile women undergoing a first embryo transfer: a systematic review and meta-analysis of published and unpublished data from randomized controlled trials. Fertil Steril 2019;111(4):734–746.e2.
9. van Hoogenhuijze NE, Mol F, Laven JSE, et al. Endometrial scratching in women with one failed IVF/ICSI cycle — outcomes of a randomised controlled trial (SCRaTCH). Hum Reprod 2021;36(1):87–98.
10. van Hoogenhuijze NE, Kasius JC, Broekmans FJM, Bosteels J, Torrance HL. Endometrial scratching prior to IVF; does it help and for whom? A systematic review and meta-analysis. Hum Reprod Open 2019;2019(1):hoy025.
11. Mackens S, Racca A, Van de Velde H, et al. Follicular-phase endometrial scratching: a truncated randomized controlled trial. Hum Reprod 2020;35(5):1090–1098.
12. Human Fertilisation and Embryology Authority. Endometrial scratching. Rated amber for most IVF/ICSI patients and grey for recurrent implantation failure; evidence reviewed July 2023.
13. Gricius R, Piesliakaitė K, Narutytė R, Austys D, Ramašauskaitė D. Impact of endometrial scratching on IVF/ICSI outcomes: a meta-analysis. J Clin Med 2026;15(9):3340.

Dr. Senai Aksoy

Dr. Senai Aksoy studied and trained in France before returning to Turkey, where he was a member of the ICSI team at Sevgi Hospital, Ankara — the country's first ICSI centre (1994-95) — and a co-author on the first Turkish ICSI publications produced in collaboration with the Brussels Van Steirteghem group (Human Reproduction, 1996; PMID 8671323). He helped build the IVF programme at the American Hospital Istanbul and has been running his own fertility practice since 1998.

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The content has been created by Dr. Senai Aksoy and medically approved.