What is an Endometrial Scratch, and should I consider it?

What is an Endometrial Scratch, and should I consider it?

Rachel and I had the opportunity during our first round of IVF to be part of one of the large scale trials trying to see if the endometiral scratch improves live pregnancy rates. We got provided with a lot of information and did a lot of research and this is what we found.

An endometrial scratch is an assisted reproduction technique which causes intentional minor damage to the endometrial lining via a small biopsy using a plastic catheter. The mechanism as to why this may help remains unclear. There are currently 3 large scale studies exploring the impacts of endometrial scratching on live birth rates.

A detailed look at endometrial scratching.

During mine and Nathan’s IVF treatment we consented to participate in a clinical trial on this procedure. We met with the research nurse who took us through the research and what it was looking to answer: it was trying to identify the impact of endometrial scratch on first time IVF pregnancy rates. We were happy to take part in any research which may help others to get pregnant through IVF.

The procedure itself involved a trip into the clinic, I was taken into a room, where they inserted a catheter through my cervix into my uterus via a speculum. As a side note, I had an unstable cervix (which Nathan fondly refered to as a wobbly womb) that day which meant that they had to clamp my cervix into place using a tenaculum which you can see pictured. I must say this part of the procedure was very unpleasant and caused a fair bit of pain, however I must note this is very uncommon and not many women need this, it did make me worry that I might need this added to my embryo transfer, however luckily enough, I think they just caught my cervix on a bad day. But the actual scratch itself wasn’t too bad and I just had minor cramps afterwards. For most women it is no more uncomfortable than a cervical smear.

There are a number of instruments which can be used to do the endometrial scratch, however the most common is a 3mm plastic biopsy catheter known as pipelle catheter. As mentioned, this is inserted through the cervix into the lining of the endometrium and moved back and forth. This is the same procedure that a normal biopsy would use.


Why might an endometrial scratch be helpful in IVF?

As mentioned in introduction paragraph it remains unclear what the mechanism is behind the possible success of the endometrial scratch is. Currently there are a couple of leading hypotheses and those are: –

Facilitation of endometrial decidualization – This is a process which causes significant changes to the function and morphology (the form) of the endometrial stromal cells (ESCs), increases the presence leukocytes (specialist white blood cells) and a change to the blood supply of the endometrium. The ultimate goal of this process is to improve placental formation and to allow for safe exchange of nutrients and gases between the mother’s blood supply and the embryo. This is a naturally occurring process which starts at ovulation and then further develops after implantation. So, the theory goes that by stimulating this response it makes implantation and placental development easier leading to a higher pregnancy rate. An interesting video from Wizscience is shown opposite

Activation of an immune response – It is shown that IVF and the use of a stimulated cycle reduced the implantation rate, one possible reason for this is that it creates an asynchrony between the endometrial and embryo stage i.e. the development of your endometrial lining and the development of your embryo are out of sync with each other meaning implantation is less likely to occur. However, it is hypothesised that the injury as a result of the scratch causes the endometrial lining to become synced with the stage of the embryo. This is because the trauma causes an immunological response designed to repair the tissues, this shared some of factors involved with embryo implantation process, these are specifically adhesion molecules, cytokines, growth factors and enzymes hence this should improve the implantation chance of the embryo. Reading the above it is also clear that if you are trying to sync up the two then timing becomes key, so it is advised that the treatment is performed immediately before ovarian stimulation drugs are started.

We don’t go into detail of an IVF procedure in this article, but the scratch takes place in the second part of your cycle. If you want to learn more about the standard IVF process then check out our article what to expect from an IVF cycle.

Will the endometrial scratch improve my chances of a successful IVF cycle?

HFEA currently rate this as amber which means there is conflicting evidence and more research is required to confirm or reject the procedure. In 2015 Cochrane who are the gold standard of research reviews in health did a study of 14 trials into the endometrial scratch. It included 1063 women and the pregnancy rate data was of moderate quality. The key result of this is that the clinical pregnancy rate of those not having endometrial scratch was 30% and those that had an endometrial scratch had between 33%-48% clinical pregnancy rate.

A small number of the studies looked at the perceived pain level of the procedure and of 5.22 out of 10, however, note that this study was of very low quality. Finally, it highlighted there was no statistically consequential increase in miscarriage rates of those having this procedure. Finally, it noted that trials of high quality need to be performed. These have been going on with 3 very large-scale studies due to have results released soon. It currently appears that these old studies may have shown a greater impact on improvement of pregnancy rates than the reality.

One of those studies has released preliminary results of 2537 women titled Endometrial scratching prior to IVF; does it help and for whom? A systematic review and meta-analysis. It’s main outcome was that clinical pregnancy rate in the endometrial scratch group was 31.4% vs 31.2% in those that didn’t have the scratch, while live birth rates were 26.1 per cent in both groups.

So, no statistically valid increase in pregnancy rates. It will be interesting to see what the other 2 studies reveal and hopefully the procedure can once and for all be deemed appropriate or not.

Does the endometrial scratch come with any risks?

The procedure itself comes with a couple of risks. The first is the pain of the procedure, some women have found the procedure moderately painful and some have experienced cramping and minor spotting after the procedure.

A more important risk to be aware of is that as it is an invasive procedure as such there is a small risk scratch site could become infected, this infection can also spread deeper into the uterine cavity, this is something that can be treated by the clinic if it happens, however it is important to know.

Should I pay for the endometrial scratch add-on?

The endometrial scratch is a simple process without the need for aesthetic, it is a quick procedure and having researched the costs of endometrial scratch it is generally between £175-£350 in a licenced private clinic in the UK. Having had the treatment as part of a large-scale study through an NHS funded cycle the lower end of this price bracket seems fair but the high end expensive. With the current body of evidence mixed and until the latest trials are analysed, we feel that it is a difficult one to recommend either way.

Our personal thoughts are that if this is your first cycle of IVF treatment then there is absolutely no need to add this onto your IVF treatment however if you have had multiple failed attempts, especially with good quality embryo’s not implanting then this may be something you consider – but please note that this doesn’t mean that it WILL increase your chance of becoming pregnant but it may help with a peace of mind and it is one of the options where there is more evidence than other procedures.


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