Canadian doctors say a new blood test conducted in the early stages of pregnancy is transforming fetal screenings because it can more accurately predict the risk of genetic disease.
The blood test analyzes fetal DNA from the baby circulating in the mother’s blood as early as 10 weeks into the pregnancy, searching for genes linked to Down syndrome.
Physicians say the test is simple and may reduce the need for more invasive fetal tests, such as amniocentesis, which uses a needle to extract fluid from the uterus and carries a risk of miscarriage.
Existing prenatal tests are also conducted later in the 11th and 13th week of pregnancy and combine ultrasound and a hormonal blood test which is less accurate, doctors say.
New mother Lisa Coolen was one of the first women in Canada to get the new prenatal test. Like other expectant mothers, she wanted to know that her baby was OK.
“I think it’s an excellent option … to get peace of mind in pregnancy and not put your baby at risk,” she said.
Dr. Sylvie Langlois, a geneticist at the Children’s and Women’s Health Centre of British Columbia, said many expectant mothers share that sentiment.
“If we offer women a safe test the majority of them will want to know, and will end up having an answer as to whether their pregnancy has Down Syndrome or not.”
But the test is not currently free. Women must pay between $800 and $1,400, depending on the commercial provider. By contrast, current screening tests cost approximately $100-$150.
Physicians are looking at how to make the test more affordable, said Dr. Nan Okun, who works in maternal fetal medicine at Mount Sinai Hospital in Toronto.
“As we work with our various ministries of health we’ll hopefully work towards a program that will incorporate it in a way that we can offer to all women without having to ask them to pay,” Okun told CTV News.
The results may also be less accurate in obese women or women carrying twins. And, unlike an ultrasound, it doesn’t provide information about structural abnormalities.
But for Coolen, the blood test gave an accurate read on the health of Peyton, who is now less than a month-old.
“She is a perfectly healthy baby and I can’t imagine having done the amniocentesis and potentially risking her at that time.”
In the future, doctors say the technology behind the testing will allow them to detect other disorders and more subtle abnormalities.
With a report by CTV Medical Specialist Avis Favaro and producer Elizabeth St. Philip
Correction:
In the TV story that aired, Dr. Sylvie Langlois from B.C. Children's Hospital and B.C. Women's Hospital (the first physician commenting in the story) was incorrectly identified as Dr. Nan Okun from Mount Sinai Hospital in Toronto.
Dr. Okun was incorrectly identified as Dr. Langlois.
We apologize for this error.