A new blood test that is said to accurately detect congenital disorders such as Down, Patau and Edwards' syndromes has been recommended for high-risk women on the National Health Service.
Called non-invasive prenatal testing (NIPT), the new screening method offers a non-invasive solution for pregnant women in determining whether their child has a congenital disorder or not.
At present, congenital anomaly screening is performed by amniocentesis, which involves obtaining amniotic fluid by injecting a needle through the pregnant woman's womb. This procedure accounts for 1 percent chance of miscarriage and one in 1,000 risk of developing infections.
With the new proposal, the process of antenatal screening may soon see a facelift. The Department of Health is now reviewing the recommendations.
"We welcome these important recommendations from the UK National Screening Committee, which have the potential to transform antenatal screening," a spokesperson says.
Current guidelines recommend pregnant women to undergo a combination of blood test and ultrasound imaging when they reach the 10th-14th week of pregnancy. In the new proposal, advisers said women who exhibit at least one in 150 chance of carrying a child with Down, Patau or Edwards' syndrome should be offered NIPT.
If doctors still have doubts about the results of the combined tests, they may still recommend patients to undergo amniocentesis.
NIPT is based on the understanding that the DNA of the developing fetus also circulates in the blood of the mother. With this, it can be said that some of the baby's genetic profile can be found and extracted in the mother's blood for analysis.
So far, experts said NIPT has shown promising results. In Great Ormond Street hospital in London, researchers concluded that the screening method is 99 percent accurate and safe, thereby drawing more patients to take the test. In fact, more than 2,500 medium to high-risk women accepted to undergo the testing.
In St. George's University Hospitals NHS foundation trust, NIPT has been available since June 2015.
Although ministers are yet to officially approve the recommendation, the UK national screening committee is positive that the test would be implemented soon.
While evidences show that NIPT is more accurate than current tests in determining Down, however, its ability to detect other congenital disorders, which are included in the national program, is still not certain.
"It is possible that in the future NIPT could replace current screening tests or diagnostic tests," writes Rapid NHS. "However, it is currently being evaluated as an additional step in the existing screening pathway."
The intention is to continue monitoring and evaluating as results surface, says Dr. Anne Mackie, director of screening at Public Health England. She added that this means implementing the test across England in such a way that experts can learn and modify the program as necessary.
Down, Patau and Edwards' syndromes are all characterized by the presence of an extra copy of chromosome 21, 13 and 18 respectively. Babies with Down have mild to severe learning difficulties, while most patients with Patau and Edwards' die before or shortly after birth.
Photo : Vladimir Pustovit | Flickr
