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Endometrial scratching
For most patients, having a routine cycle of proven fertility treatment is effective without using any treatment add-ons.
Our ratings indicate whether the evidence from studies shows that a treatment add-on is effective at improving treatment outcomes for someone undergoing fertility treatment. Our rating do not tell you how much that treatment add-on improves your chances of having a baby – please discuss this with your clinic.
What is endometrial scratching?
In order to have a successful pregnancy, an embryo needs to ‘implant’ in the womb; if it doesn’t, the patient will need to start their cycle again.
Most embryos don’t implant because they have been unable to develop fully to the implantation stage or because of a developmental mismatch between the stage of the embryo and the lining of the womb. In a small number of cases an embryo won’t implant because the lining of the womb isn’t providing them with the right environment.
Endometrial scratching (also known as endometrial injury) is carried out before IVF. During the procedure the lining of the womb (the endometrium) is ‘scratched’ using a small sterile plastic tube.
The theory is that this procedure triggers the body to repair the site of the scratch, releasing chemicals and hormones that make the womb lining more receptive to an embryo implanting. Some also suggest the treatment may activate genes that make the womb lining more receptive to an embryo implanting.
| Rated outcomes for endometrial scratching | |
|---|---|
| Rated amber for increasing the chances of having a baby for most fertility patients undergoing IVF or ICSI
Yellow traffic light
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For most fertility patients undergoing IVF or ICSI, the use of endometrial scratching is rated amber for improving the chances of having a baby. This is because, on balance, it is not clear whether this add-on is effective at improving the treatment outcome. This is because there is conflicting moderate/high quality evidence – in some studies the add-on has been found to be effective, but in other studies it has not. This rating does not apply to patients undergoing IUI given that many of the high-quality studies that were assessed did not include patients undergoing IUI. |
| Rated grey for improving the chances of having a baby for patients with recurrent implantation failure (RIF)
Grey traffic light
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We cannot rate the effectiveness of this add-on at for improving the chances of having a baby for patients with RIF as there is insufficient moderate/high quality evidence. |
What do the ratings mean?
There are five ratings that indicate whether a treatment add-on is effective at improving treatment outcomes for someone undergoing fertility treatment, according to the evidence from studies. To make it easier to understand the scientific evidence for each treatment add-on we have a range of symbols and colours for each rated add-on below.
Green traffic light
On balance, findings from high quality evidence shows this add-on is effective at improving the treatment outcome.
Yellow traffic light
On balance, it is not clear whether this add-on is effective at improving the treatment outcome. This is because there is conflicting moderate/high quality evidence – in some studies the add-on has been found to be effective, but in other studies it has not.
Grey traffic light
We cannot rate the effectiveness of this add-on at improving the treatment outcome as there is insufficient moderate/high quality evidence.
Black traffic light
On balance, the findings from moderate/high quality evidence shows that this add-on has no effect on the treatment outcome.
Red traffic light
There are potential safety concerns and/or, on balance, findings from moderate/high quality evidence shows that this add-on may reduce treatment effectiveness.
All treatment add-ons on our list will have a rating to indicate whether the evidence shows that the treatment add-on is effective at improving the chances of having a baby for most fertility patients. Some treatment add-ons on our list may also have additional ratings for specific treatment outcomes. For example, whether the evidence shows that the treatment add-on reduces miscarriage. There may also be further ratings for specific patient groups, for example whether the evidence shows that the treatment add-on is effective for those who are aged over 40. Please see the individual webpages for each treatment add-on for their ratings.
An agreement between the HFEA and other professional and patient bodies (the 19th October 2023 consensus statement) states that treatments that have no strong evidence of their safety and/or effectiveness should only be offered in a research setting. Patients should not be charged extra to take part in research, including clinical trials.
What’s the evidence for endometrial scratching?
A number of high-quality studies have been completed to date with conflicting results. Further evidence is needed before the benefits of endometrial scratching can be confirmed.
Studies investigating endometrial scratching focused on patients undergoing IVF or ICSI, and therefore these ratings do not apply to patients undergoing IUI. In addition, there were no moderate/high quality studies explicitly investigating patients with RIF, therefore there is no evidence that endometrial scratching is beneficial for this patient group either.
At the July 2023 Scientific and Clinical Advances Advisory Committee (SCAAC) meeting the Committee evaluated the evidence base for endometrial scratch. Minutes of this discussion and the evidence used to inform this are available on the SCAAC webpage.
This Cochrane review has further information on the evidence for endometrial scratching.
Is this treatment add-on safe?
This is an intrusive and potentially painful procedure, with some patients experiencing some blood loss. It is not common for patients to have an infection after the scratch but there is a small risk that if you have an infection within your cervix before ‘scratching’, this may cause the infection to spread into the uterus. Your clinic can treat this if necessary. Endometrial scratching does not carry any additional known risks for the child born as a result of fertility treatment.
If you have any questions about the safety and risks, your clinic will be able to discuss whether a treatment add-on would be safe for you to use considering your specific medical history and circumstances.
Studies reviewed for this treatment add-on
The SCAAC have reviewed the following studies for endometrial scratching:
| Raziel 2007 | 10.1016/j.fertnstert.2006.05.062 |
| Zhou 2008 | 10.1016/j.fertnstert.2007.05.064 |
| Karimzadeh 2009 | 10.1111/j.1479-828X.2009.01076 |
| Narvekar 2010 | 10.4103/0974-1208.63116 |
| Abdelhamid 2012 | 10.1007/s00404-013-2785-0 |
| Nastri2013 | 10.1002/uog.12539 |
| Gibreel 2013 | 10.1111/j.1447-0756.2012.02016.x |
| Parsanezhad 2013 | IRCT:2012082510657NI |
| Zarei 2014 | IRCT:2012070810210NI |
| Wadhwa 2015 | J Hum Reprod Sci 2015;8(3):151-8. |
| El Khayat 2015 | 10.1016/j/ejogrb.2015.08.025 |
| Gibreel 2015 | 10.3109/09513590.2014.994603 |
| Maged 2016 | 10.1177/1933719115602776 |
| Bahaa Eldin 2016 | 10.1177/1933719116638191 |
| Goel 2017 | 10.1007/s10815-017-0949-8 |
| Mak 2017 | 10.1016/j.rbmo.2017.04.004 |
| Aleyamma 2017 | 10.1016/j.ejogrb.2017.05.005 |
| Helmy 2017 | 10.1002/ijgo.12178 |
| Senocak 2017 | 10.1016/j.jogoh.2017.09.003 |
| Ashrafi 2017 | 10.1111/jog.13401 |
| Maged 2018 | 10.1002/ijgo.12355 |
| Hilton 2019 | 10.1007/s00404-019-05044-9 |
| Eskew 2019 | 10.1007/s10815-018-1356-5 |
| Frantz 2019 | 10.1093/humrep/dey334 |
| Lensen 2019 | 10.1056/NEJMoa1808737 |
| Olesen 2019 | 10.1016/j.fertnstert.2019.08.010 |
| Mackens 2020 | 10.1093/humrep/deaa018 |
| Tang 2020 | 10.1111/jog.14193 |
| Berntsen 2020 | 10.1016/j.ejogrb.2020.06.034 |
| Ghuman 2020 | 10.1016/j.ejogrb.2020.08.010 |
| Rodriguez 2020 | 10.1007/s43032-020-00204-8 |
| van Hoogenhuijze 2021 | 10.1093/humrep/deaa268 |
| Metwally 2021 | 10.1093/humrep/deab041 |
| Yavangi 2021 | 10.18502/ijrm.v19i5.9255 |
| Glanville 2022 | 10.1016/j.rbmo.2021.10.008 |
| Izquierdo 2022 | 10.1016/j.jogoh.2022.102335 |
| Madhuri 2022 | 10.1016/j.ejogrb.2021.10.028 |
| Metwally 2022 | 10.3310/JNZT9406 |
| Wong 2022 | 10.1016/j.fertnstert.2021.12.009 |
| Baum 2012 | 10.3109/09513590.2011.650750 |
| Zhang 2014 | 10.1007/s00404-014-3382-6 |
| Zhang 2015 | 10.1007/s11655-014-1843-1 |
| Bord 2015 | 10.1007/s00404-015-3954-0 |
| Siristatidis 2017 | 10.1080/09513590.2016.1255325 |
| Gürgan 2019 | 10.1016/j.rbmo.2019.02.014 |
| Tumanyan 2019 | 10.1080/09513590.2019.1632085 |
| Aghajanpour 2021 | 10.1016/j.jri.2021.103426 |
What are treatment add-ons?
In vitro fertilisation (IVF) and intrauterine insemination (IUI) are established treatments that have been proven effective for most patients. Treatment add-ons are optional non-essential treatments that may be offered in addition to such proven fertility treatment. The HFEA provides information on add-ons that meet the following criteria:
- Additional treatments (to the core treatment e.g. IVF or IUI), that are being offered to the general patient population in licensed fertility clinics in the UK,
- Where there are published scientific studies which claim to demonstrate that the treatment add-on improves the chances of having a baby or other treatment outcomes rated by the HFEA; but
- where evidence of effectiveness for the use of the treatment in a clinical setting is lacking or absent; and
- where patients need unbiased information about the effectiveness and risks of this treatment.
It is important to keep in mind that for most patients, having a routine cycle of proven fertility treatment is effective without using any treatment add-ons. If you are paying directly for your own treatment, you may want to think about whether it might be more effective and/or affordable to pay for multiple routine proven treatment cycles, rather than spending large sums of money on a single treatment cycle with treatment add-ons that haven’t been proven to be effective at increasing the likelihood of you having a baby.
We aim to publish clear and reliable information about some of the treatment add-ons that don’t have enough evidence to show that they are effective at improving your chances of having a baby and other relevant treatment outcomes. This provides useful information to patients and allows them to question the use of add-ons.
Review date: 19 October 2025
