Using fetal DNA to detect chromosomal abnormalities following miscarriage

Tommy’s researchers want to find out whether a simple blood test can be used to find out whether a miscarriage was caused by a problem with the baby’s chromosomes.
  • Authors list

    Professor Tom Bourne, Dr Nina Parker, Stephanie Allen

Why do we need this research?

More than half of all miscarriages occur because of a chromosomal abnormality. This is where the baby carries too many or not enough chromosomes and is not able to develop properly. In the UK, pregnancy tissue will only be checked for chromosomal abnormalities after a woman has experienced recurrent miscarriage, defined as three or more miscarriages in a row. In clinical practice, this is further limited to women who have had surgery to remove pregnancy tissue from the womb, and it can take weeks or months to receive a result.

In order to provide women with the answers they need, we must have better ways of working out whether a genetic abnormality was the cause of miscarriage.

What’s happening in this project?

Researchers funded by Tommy’s have already looked at whether something called cell-free fetal DNA (cffDNA) can be used to find out whether a miscarriage was caused by a genetic problem with the baby. cffDNA is shed from the placenta into the mother’s blood, where it can be picked up in a blood sample. Currently, cffDNA testing is used in the second and third trimester of pregnancy to find out the sex of a baby and to diagnose genetic diseases. Several small studies have already indicated that cffDNA testing may help to identify whether or not a miscarried baby had any chromosomal abnormalities, and our team want to find out more. 

Our researchers are carrying out a study that will look at cffDNA results from 300 women who had either a missed miscarriage – where the baby dies in the womb but the mother has no symptoms, such as bleeding or pain – or an incomplete miscarriage – where the pregnancy tissue doesn’t completely come away from the womb. cffDNA will be analysed from blood collected from both one-off and recurrent miscarriages, and the pregnancy tissue will also be tested to check whether any chromosomal abnormalities were present. By doing this, it will be possible to work out how accurately cffDNA testing can detect a chromosomal abnormality following miscarriage.

Moving forward, the team also want to find out what psychological impact chromosomal testing following a miscarriage has on women and their partners.

What difference will this project make?

This project will confirm whether cffDNA testing can be used to work out whether a miscarriage has occurred because there was a problem with the baby’s chromosomes. If successful, it would mean that women and their partners could get this information from a simple blood test, finding out the results in days instead of weeks or months. As cffDNA analysis does not rely on the collection of pregnancy tissue, this test would also increase the number of women who are able to access chromosomal testing, meaning that more women will be able to find out why their miscarriage happened.