It’s hard to imagine what it would feel like to have the lining of your womb deliberately injured. But many women who populate the #TTC (trying to conceive) communities on Instagram have firsthand experience. It’s been described as hurting "like a bitch" and "the most painful 5 seconds I’ve ever felt (so far)". One woman, who says she normally has a high pain threshold, wrote: "It made me yelp and even shed a tear."
What is endometrial scratching?
This painful process, known as an endometrial scratch, is a form of fertility treatment – a so-called add-on to help shore up the success of IVF. But evidence that the practice works is rocky and the reasons for its usage are complicated.
Endometrial scratching describes a process which is carried out before IVF. The procedure involves scratching the endometrium (the lining of the womb) using a small sterile tool.
Dr Raj Mathur, chair of the British Fertility Society and spokesperson for the Royal College of Obstetricians and Gynaecologists (RCOG), explains: "The aim of this is to increase the chances of the embryo successfully implanting itself into the lining of the womb, allowing the woman to become pregnant. The theory is that the scratching will release chemicals and hormones to make the endometrium more receptive to the embryo implanting." The procedure costs on average between £150 and £300, making it a relatively low-cost addition (in the context of fertility treatments).
Research in recent years into whether scratching your endometrial wall helps fertility is conflicting, according to Sarah Lensen, a subfertility researcher and clinical trialist at the University of Melbourne.
"If we consider only randomised controlled trials (generally considered to be the highest quality study), some trials report benefit from the procedure and others report no effect or even a reduced chance of conception," she tells R29. However, Sarah says that a lot of these studies have very serious limitations that make their results unreliable. This is reflected in the amber traffic light rating awarded to the scratch by the Human Fertilisation and Embryology Authority (HFEA) – a sign that there is limited evidence to support the benefits of a fertility add-on.
What are the risks of endometrial scratching?
There are additional risks (however small) with the procedure, including light vaginal bleeding and a small risk of infection. And of course there’s the pain of the procedure itself. Because of this, in Sarah’s view: "There is no good evidence that endometrial scratching can help women have a baby from IVF."
In a statement to Refinery29, the British Fertility Society, the RCOG and Fertility Network UK echo that sentiment – with caveats.
Gwenda Burns, chief executive of Fertility Network UK, says: "We would advise anyone considering paying for additional tests or treatments to check the information given by the fertility regulator, the Human Fertilisation and Embryology Authority (HFEA), to help them to make an informed decision."
Similarly, the RCOG and British Fertility Society say they do not support endometrial scratching being routinely offered to people and couples undergoing IVF as "current evidence is conflicting, and while not a harmful procedure, it is intrusive and can be painful."
They add: "Anyone who is considering endometrial scratching as a fertility add-on should be made fully aware of the current conflicting evidence, any risks and the cost, to allow them to make an informed decision."
Natalie, 26, had an endometrial scratch done ahead of her first embryo transfer in October 2021, after being diagnosed with unexplained infertility in August. "They told me it would give me a higher chance of the embryo implanting," she tells R29, describing it as "quite uncomfortable but bearable, like a smear test". Though her first round of IVF wasn’t successful, she feels that the procedure was beneficial "because at the time I thought it’s going to give us the best chance". She is now embarking on a second round of IVF with a different clinic.
Marie, 39, had her endometrial scratch back in 2016 when there was less known about the efficacy of the procedure, ahead of an unsuccessful round of IVF in 2017.
"I was advised to have an ES (endometrial scratch) in 2016 via the NHS. In hindsight it was the wrong advice for me and it caused me significant pain, stress and trauma because at the time I had multiple gynaecological issues that were not fully under control."
There are instances of success and times when the treatment is still offered. Julija Gorodeckaja, deputy group medical director at Care Fertility in the UK, tells R29 that while the endometrial scratch "probably doesn't help every woman, there is a place for it on the market".
Who can receive an endometrial scratch?
Care Fertility now offers the endometrial scratch for two patient groups. The first group are patients who’ve already had a successful IVF cycle with an endometrial scratch and are coming in for their second baby, and believe that the endometrial scratch contributed to their success. Julija says it’s best for both patient and practitioner to follow the same treatment plan again if you have a successful treatment cycle. "If you do the same treatment that was successful in the past and it’s now not successful, that’s accepted more favourably because we know that fertility treatment doesn't work 100%." In other words, if you change something and the treatment then doesn’t work, you’ll probably attribute the lack of success to what you changed, not bad luck or physiology or the fact that fertility treatment doesn't always work. The second group, Julija says, are the IVF patients who should theoretically be able to conceive (either because they are young or they have good quality embryos, either from their own eggs or donated eggs) but don't, for whatever reason.
According to research that Sarah worked on, which was published in December 2021, the most common benefit of the endometrial scratch reported by clinicians was not necessarily a successful pregnancy. "The most common benefit reported was that, for patients who strongly request endometrial scratching, making it available to them reduces their psychological distress. A third of clinicians also said it offers women hope and motivation to continue with IVF. This is in comparison to only 8% who thought it would improve the probability of pregnancy." This psychological aspect is arguably at play when the endometrial scratch is repeated for the second time after a successful pregnancy, as the benefit of the scratch is as much to do with not adding variables which could lead to more distress.
Although Julija and Sarah tell R29 that the endometrial scratch is usually offered after patients have experienced a number of failures with standard IVF, that is not always the case. It gets complicated when patients, who are increasingly educated about the process, come in asking for particular treatments.
Fertility patients are more informed than ever about treatments and research, thanks to communities like #TTC on Instagram. That knowledge can sometimes butt heads with the distress and desire to conceive, leading patients to pursue painful treatments unnecessarily in the hope that they will help them to conceive.
"We're trying to be very transparent for the patient," says Julija. "It is true that patients these days are very well educated, they come with a very, very solid knowledge and also they come with very strong opinions about what they want and don't want. Sometimes it is a challenging conversation to talk them out of things that they believe they need."
As Gwenda puts it: "We understand how distressing it is not to be able to have a child, and that many want to do anything that might possibly help them to conceive a much longed for baby. However, it is important to be aware of the evidence before making decisions."