Endometrial scratching for IVF

What is Endometrial scratching for IVF?

A procedure to scratch or disturb the lining of the uterus (endometrium)

• Endometrial scratching is a procedure which involves ‘scratching’ or disrupting the endometrium (lining of the uterus).
• The procedure is essentially the same as an endometrial biopsy procedure. Endometrial biopsies are usually done to collect a sample of endometrial tissue to check for possible problems like abnormal cells or infection. The procedure has just been renamed as ‘endometrial scratching’ when it is used in the context of an IVF cycle.
• The procedure usually uses a thin plastic straw called a pipelle. It is placed through the cervix and into the uterus where it is moved back and forth and rotated to take a sample of the endometrium which is considered to ‘scratch’ the surface of the endometrium. The pipelle and the sample are usually discarded.

Why might endometrial scratching improve IVF outcomes?

• During endometrial scratching, the mechanical action of taking the sample may cause an injury or ‘scratch’ to the endometrium. This injury may trigger the body's natural healing and immune response, including the release of growth factors, cytokines, and immune cells.
• Many of these immune cells and cytokines are known to play an important role in embryo implantation and pregnancy.
• It is suggested that endometrial scratching before IVF might increase the levels of cytokines and immune cells and that this might help to make sure the endometrium is ready and able to allow an embryo to implant.

Why might endometrial scratching not improve IVF outcomes?

• The endometrium already has the presence of immune cells, cytokines and growth factors. Most patients probably don’t have a problem with the immune system in their endometrium being overactive or underactive.
• The rationale for endometrial scratching assumes that some patients have lower levels of immune cells and cytokines than are required for successful implantation. However, this has not been proven as the results of scientific studies have been mixed. This means that, although it is possible that some patients may benefit from endometrial scratching, other people who have an endometrial scratch may have a reduced chance of getting pregnant.
• Endometrial scratching is typically performed in the menstrual cycle before an IVF cycle. This means that, after the scratch, the person usually experiences a menstrual period before the embryo transfer. It is unclear how any potential benefits from the scratch might persist, as the endometrial lining is shed during menstruation, and a new lining subsequently forms.
• It is important to remember that implantation failure is common - most embryo transfers do not result in pregnancy. Most of the time when embryos fail to implant it is due to genetic or chromosomal problems in the embryo itself, rather than issues with the endometrial lining. Therefore, endometrial scratching may not be expected to make much difference to the chance of successful implantation.

Who might consider endometrial scratching for IVF?

People who have experienced recurrent implantation failure

Does endometrial scratching for IVF work? What the evidence says

Endometrial scratching might increase the probability of getting pregnant and having a baby from IVF. A large number of trials have evaluated endometrial scratching in IVF, although some had flaws or limitations that could bias their results. While many trials suggest a potential benefit, results are conflicting, and some of the largest studies have found no advantage.

Side effects of endometrial scratching

Is endometrial scratching painful?

The most common side effect of endometrial scratching is pain - studies report pain scores of around 4 out of 10.

Other side effects of endometrial scratching

• The endometrial biopsy procedure is considered safe and serious complications are rare.
• Rare side effects include:
  • Prolonged bleeding
  • Infection
  • Uterine perforation (making a hole in the wall of the uterus) but this is extremely rare
  • Feeling faint for a short time during and after the procedure
• A possible risk of the procedure is endometrial adhesions, especially if infection occurs, which may require further treatment and could make it more difficult to get pregnant. However, this is very rare.
• In some cases, the endometrial scratch may be undertaken as part of a surgical procedure, such as a hysteroscopy, which has its own, separate risks. A hysteroscopy is a surgical procedure where an instrument is inserted through the vagina and cervix so the doctor can look inside the uterus. This may be performed under a general anaesthetic.

All medical procedures carry some risk.

Risks of endometrial scratching and long-term outcomes

There are no known risks or long-term harms

• This is based on data from randomised controlled trials and input from IVF specialists. Possible risks of harm and long-term outcomes are often not reported in randomised trials and therefore it is unknown whether endometrial scratching poses any risk of harm to the IVF patient or the embryo/baby

Endometrial scratching has been used in Australia since 2013 and approximately 10,000 IVF cycles have used endometrial scratching.

Cost of endometrial scratching for IVF

Endometrial scratching usually costs between $400-800 AUD. At times, the procedure may be undertaken as part of another procedure, such as a hysteroscopy which is a procedure to look inside the uterus, and this may incur additional costs.

Cost information is indicative only, costs can vary from clinic to clinic and depending on different circumstances.

Practical considerations about endometrial scratching

Endometrial scratch procedure

Endometrial scratching is similar to a smear test, but tends to be more uncomfortable. First, a speculum is placed inside the vagina. Then a thin plastic catheter, usually a pipelle, is inserted through the cervix and into the uterus. The catheter is gently moved back and forth and rotated around, in multiple areas, and a sample of the endometrium is collected at the same time. The catheter is then removed and discarded. The procedure can usually be performed without any anaesthetic and takes approximately 5 minutes. The procedure may require an additional visit to the IVF clinic. If the procedure is undertaken as part of hysteroscopy procedure, it may require a hospital admission.

Sometimes the procedure is difficult for the clinician to perform, and it may be necessary to use additional techniques such as a tenaculum. In about 3% of people the procedure may not be possible.

Timing of endometrial scratch

The endometrial scratch procedure is usually performed around day 21 of the cycle before the IVF or embryo transfer cycle. Patients will usually be advised to avoid unprotected intercourse in this cycle.

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