What is endometrial scratch?

In order to have a successful pregnancy, an embryo needs to ‘implant’ in the womb.

Most embryos don’t implant because they’ve been unable to develop fully to the implantation stage or because of a developmental mismatch between the embryo and the lining of the womb.

However, in a small number of cases an embryo won’t implant because the lining of the womb may not be providing them with the right environment.

Endometrial scratching is carried out before IVF. During the procedure the lining of the womb (the endometrium) is ‘scratched’ using a small sterile plastic tube. Small pieces of tissue are removed in this process.

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.

Risks of endometrial scratching

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.

Research

There have been nineteen RCT’s looking at the effects of endometrial scratch. Some have shown consistent moderate evidence supporting scratch. Two studies showed no effect.

More recently in 2019 two large studies have been reported. One was stopped before the end although it was felt that it could not be sure that a benefit did not exist.

It appears that analysis of larger trials including IVF and ICSI patients probably show no benefit although possibly some evidence for IUI cycles.

Current HFEA grading

For more information, please visit the HFEA website