More than half of miscarriages are related to genetic problems in the baby. However, when it happens, many parents aren’t given a reason why.
For years, tests in the second and third trimester have used a baby’s DNA to find out the sex of the baby, as well as to diagnose genetic diseases. This DNA – known as cell-free fetal DNA (cffDNA) – is shed from the placenta into the mother’s blood, where it can be picked up by simple blood testing. This is called Non-Invasive Prenatal Testing, or NIPT.
So far, this type of test has not been used in early pregnancy. However, we think that testing the baby’s DNA in this way will help give parents who have suffered miscarriage an explanation for their loss.
A recent small-scale study looked at 50 women who had had miscarriages, and managed to detect DNA in 38 women. Of these pregnancies, 8 babies had extra chromosomes. Depending on where the extra chromosome is accidentally added, the baby can develop Down’s syndrome or a number of other genetic disorders.
The positive conclusion was that cffDNA stays in the mother’s blood as long as the placenta is still in the womb. On the basis of these results, we are carrying out a larger trial, looking at 320 women suffering from miscarriage over 2 years. We will take blood samples from all women to look at the cffDNA and see if we can find out if there were genetic reasons for miscarriage.
We hope that in the future this research will help us to give parents explanations, where before they were simply left without a reason.
Stephanie Allen, Graham Fews, Susan Hamilton, Emily Colley, Fiona Togneri, Arri Coomarasamy, Abey Eapen, Paul SmithHide details
This study is fully funded by Tommy's and takes place in a Tommy's centreHide details