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 or birthing person has experienced recurrent miscarriage, defined as three or more miscarriages in a row. In clinical practice, this is further limited to people 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 families with the answers they need, we must have better ways of working out whether a chromosomal abnormality was the cause of miscarriage.
What’s happening in this project?
For several years, researchers funded by Tommy’s have been looking 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 350 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. The team are analysing cffDNA from blood collected at the time of miscarriage and are also testing the pregnancy tissue to check whether any chromosomal abnormalities were present. Our researchers already have preliminary data from 35 patients, and so far, both tests appear to give similar results.
Moving forward, the team also want to explore the psychological impact that chromosomal testing can have on women, birthing people and their partners.
What difference will this project make?
This project will confirm whether cffDNA testing can be used to accurately work out whether a miscarriage has occurred because there was a problem with the baby’s chromosomes. If successful, it would mean that families 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 and birthing people who are able to access chromosomal testing, meaning that more families will be able to find out why their miscarriage happened.
