This Non-Invasive Test Transforms Down Syndrome Detection
What is Non-Invasive Prenatal Testing?
If you're newly pregnant, you may have heard about a non-invasive prenatal blood test that tests for specific chromosomal abnormalities that once only could be detected through an invasive test. The test uses a blood sample from the mother to collect fragments of what’s called cell-free fetal DNA, which is then analyzed for certain chromosomal abnormalities. The test also can determine the baby’s gender.
While it's not currently recommended for all pregnant women, it’s already proving an invaluable tool for those who meet certain criteria. The following criteria make a women good candidates for non-invasive prenatal blood testing:
- Women at high risk for having babies with chromosomal abnormalities. This includes pregnant women at or over the age of 35, those with relevant medical histories, and those who have had unusual/abnormal ultrasound or first trimester screening results.
- Women who are carriers of rare X-linked related diseases (disorders in which knowing the baby’s sex would be beneficial).
The test can be performed as early as 9-10 weeks gestation depending on the patient’s medical history, and results usually take 7-10 business days. Several different labs perform the test nationwide under names like MaterniT21, Harmony, Verifi and Panorama.
“I’ve been waiting 25 years for a test like this to become available for my patients,” says Virtua maternal-fetal medicine specialist Ronald Librizzi, DO. “For women with certain risk factors, having the test done is a no-brainer. Overall, it reduces the number of pregnant women undergoing amniocentesis.” Although generally safe, amniocentesis does pose a small risk of miscarriage.
What the Test Will Tell You
The number of abnormalities that the MaterniT21 test detects has already grown, and this number will continue increasing in the coming years. “There’s a tremendous amount of ongoing research into this revolutionary test,” says Dr. Librizzi. “I would expect the panel [of detectable mutations] to grow once or twice a year, at least. While currently it's a very specific test for a specific group of women, it's a great first step that could soon benefit many others.”
Updated August 10, 2016