Endometrial Scratch Trial

The challenges

In vitro fertilisation (IVF), with or without intracytoplasmic sperm injection (ICSI), is a widely used reproductive technique in women unable to conceive naturally.  An array of expensive ‘add-on’ treatments are often offered, many of which lack robust evidence to support their use. One such add-on is the endometrial scratch (ES) procedure, where the endometrium is abraised prior to embryo transfer, which is hypothesised to increase the chances of live birth by improving embryo implantation.

However, in women undergoing their first IVF cycle, several controlled trials have identified contradictory evidence, with the most recent systematic review concluding that there is a lack of high-quality evidence. Many of these previous studies included both women undergoing their first IVF cycle, and women undergoing subsequent cycles, and were therefore not powered to detect clinically worthwhile effects in those undergoing their first IVF cycle. 

Fertility treatment has a significant cost burden to the National Health Service (NHS) and patients, with the cost to the NHS estimated to be around £68 million per year (based on 2013 costs). The number of first IVF cycles funded by the NHS has been decreasing over recent years, with 58% of first cycles funded by the NHS in 2017, reducing to 52% in 2018.

Given that the average patient receives three cycles of IVF, and a single IVF cycle can cost £5000, the cost of IVF treatment is a significant burden to patients. Additionally, loss of productivity due to the emotional and physical effects of IVF treatment has been estimated at £540 (€596, converted in 2020) per woman per IVF cycle in one study. The cost of IVF is increased further if the couple decides to undergo the ES procedure, despite a lack of evidence to suggest it is effective or safe. The ES is estimated to cost £325 per cycle – a cost that does not take into account the potential pain of receiving the procedure and potential healthcare contacts if the procedure is in fact unsafe. Therefore, any increase in LBRs in the first cycle of IVF will prevent patients from receiving subsequent IVF cycles, therefore reducing this burden.

A high-quality randomised controlled trial (RCT) was required to definitively conclude if the ES procedure is clinically effective, cost-effective and safe.

The research

The trial was a pragmatic, two-arm, superiority, open-label, parallel-group, multicentre, individual RCT undertaken at 16 fertility units in the United Kingdom, two of which were run privately. Participants were randomised to receive either the ES procedure followed by usual care, or usual IVF care only (treatment as usual (TAU)).

1048 female participants aged 18 to 37 years (inclusive) and undergoing their first cycle of IVF were recruited (other eligibility criteria were also applied).

The ES procedure was performed by a doctor or nurse in the mid-luteal phase of the menstrual cycle preceding IVF. ES was performed by inserting a speculum into the vagina. A pipelle or similar device was then inserted into the cavity of the uterus and negative pressure was applied by the withdrawal of the plunger. The sampler was rotated and withdrawn three to four times so that tissue appeared in the transparent tube. 

TAU participants received IVF treatment (with or without ICSI) according to the usual care practice of their fertility unit. ES participants received the ES procedure followed by TAU.

The results

Although the live birth rate was 1.5% higher in the endometrial scratch group (38.6%) compared to the control group (37.1%), the difference was not large enough to show any benefit of having the procedure.

Other outcomes did not differ significantly between the two groups. However, the procedure was safe and tolerable. We found that the costs were on average £316 more expensive for those that received the endometrial scratch, compared to the control group; the difference was not large enough to show that receiving endometrial scratch was more cost-effective.

We combined the results of this trial with previous trials that looked to answer a similar question, showing that, overall, the endometrial scratch does not enhance the chances of achieving a live birth. 

The impact

We recommend that ES should not be undertaken in women undergoing their first cycle of IVF.

The results of the trial were presented by Mostafa Metwally at the European Society of Human Reproduction and Embryology (ESHRE) conference in July 2020.

A press release was also undertaken by ESHRE. 

There were other press releases from Sheffield Teaching Hospitals and the NIHR:  New research suggests IVF ‘scratch’ offers no benefit to women undergoing IVF for the first time

Publications

The results from the trial have been published in the Journal of Human Reproduction. A full report of the research has also been published in the NIHR Journals Library.

At the end of the trial we undertook a systematic review in order to combine the results of our trial with other similar trials - this was published in Reproductive BioMedicine Online.

We also undertook a qualitative study regarding the experience of women taking part in the trial. This was published in BMJ Open.

A summary of the role of endometrial scratch in IVF treatment has been published in Seminars in Reproductive Medicine.

Project team