Blood test on mother for foetus
A SIMPLE blood test developed at UniSA could soon be used to pick up a wide range of foetal abnormalities, from cystic fibrosis to inherited cardiac problems and spinal muscular atrophy.
The test would be safer than invasive procedures that risk miscarriages.
Researchers have isolated “extremely rare” foetal cells from maternal blood – about one in every million cells – using a tiny device that lets them accurately test for almost any potential genetic problem in a baby.
Despite its size, the special design of the device, known as “lab-on-a-chip”, allows large volumes of blood to be screened.
That paves the way for an efficient, cheap and quick method of separating foetal cells from maternal blood cells.
Biomedical engineer Dr Marnie Winter said it was hoped the device could result in a new, non-invasive prenatal diagnostic test.
Current tests involve an invasive amniocentesis procedure, drawing fluid from the amniotic sac around the foetus, or taking a sample of cells from the placenta. They carry a risk of inducing miscarriage.
“From about five weeks into the pregnancy, foetal cells originating from the placenta can be found in a mother’s bloodstream,’’ Dr Winter said.
“Using modern microfluidic technology, we can now isolate these extremely rare cells from the mother’s white blood cells and collect them for genetic analysis.”
Researchers adapted the device from one initially developed to isolate tumour cells from the blood of cancer patients.
“Many pregnant women would be aware of the new tests based on circulating foetal DNA that, with a simple blood test, help determine the risk of having a baby with Down syndrome,’’ Dr Winter said. “These tests have revolutionised prenatal care, but they can only detect a small subset of genetic conditions and are not always accurate.
“We hope this LOC (lab-ona-chip) technology will be able to reliably detect a greater range of genetic abnormalities, providing more information to families and healthcare providers.”
Researchers are now collaborating with industry partners to translate the technology into routine clinical prenatal diagnostics.
The test, which Dr Winter hoped would be available in the next five years, would be for screening low and medium-risk pregnancies and would be conducted at around 11 weeks into pregnancy.