The SiM trial: can scratching the lining of the womb encourage healthy pregnancy?

Evidence suggests that problems with the lining of the womb – the endometrium – are related to having multiple miscarriages.

Even though it seems strange, we think that scratching the lining of the womb on purpose before pregnancy could help stop this from happening. The SiM (Scratch in Miscarriage) trial is testing whether this could work, and if women would be happy to try it. Even in its early stages, it has captured the public imagination, and up to 83% of women approached to take part chose to become involved.

Women taking part are under 40, and have suffered from 2 or more miscarriages in a row. Each woman will be randomly put into one of two groups, but won’t know which. One group of women will have their endometriums scratched before pregnancy, between ovulation and getting their period. The other group will simply have an examination of their cervix, but won’t be able to tell whether or not they have been scratched. 

For women in the scratching group, doctors will insert a long, thin device into the vagina and through the cervix. While pressing against the lining of the womb, they will move the device up and down for around 15 seconds, which should be enough to create a small scratch. They will also take a sample of endometrium for further study.

After they conceive, we will then follow each woman throughout pregnancy. This will let us see if women who had their endometriums scratched before pregnancy are more likely to have healthy pregnancies, and less likely to miscarry.  By studying the endometrial samples, scientists will also be able to look for new ways of testing for endometrial problems in women with multiple miscarriages. We hope this will lay the foundation for a much bigger clinical trial in the future.