What is cell-free fetal DNA?
Cell-free fetal DNA (cffDNA) is fetal DNA circulating freely in the maternal blood. Testing of the fetal DNA allows your provider to look at the baby's chromosomes. So, why is this important? This test can tell you if your baby is at higher risk of Down's syndrome or other chromosomal abnormalities such as trisomy 18, 13 or monosomy X (Turner's syndrome) as well as the gender of the baby.
What are the requirements for testing?
You need to be at least ten weeks pregnant and testing requires a blood sample.
Why is this test such a big deal in genetic screening?
Prior to this technology the only way to screen for genetic abnormalities was to have an ultrasound at 11 weeks and additional blood test to determine if you were at high risk for chromosomal abnormalities. If you tested positive you would need invasive testing such as CVS (scraping of the placenta) or an amniocentesis (needle placed into the abdomen and through the uterus to obtain a sample of cells in the amniotic fluid) to confirm a chromosomal abnormality. While these latter types of testing are very accurate, the testing is invasive and there was a small percentage of fetal loss associated with both procedures.
What do my test results mean?
If your test results are negative (normal), the likelihood of the baby actually having a chromosomal abnormality is less than 1/10,000. However, since cffDNA is a screening test, if the test results are positive (abnormal), you would be referred to a maternal fetal medicine specialist to determine if additional testing is necessary.
What do we offer at Teton Women's Health Center?
We offer cffDNA testing to all our pregnant patients. Make an appointment today and come in to speak with one of our providers about whether genetic testing with cell-free fetal DNA is the right choice for you and your baby.