The What, Why and Who of Cell-Free DNA Testing
Good News! We now have a sophisticated noninvasive blood test for pregnant women who are recommended to have a fetal DNA test because their pregnancy has an elevated risk for birth defects.
This form of fetal testing, with which many women are not familiar, is an important advancement that detects the most common chromosomal problems in the first trimester blood draw. While noninvasive cell-free testing might cause anxiety, it might help avoid the need for more invasive tests, treatment or monitoring during pregnancy.
Cell-free DNA testing poses no physical risks to you or your baby. Keep in mind, however, that cell-free prenatal testing doesn’t screen for all chromosomal or genetic conditions.
If you are interested in noninvasive prenatal testing, talk to your Genesis OB/GYN about its availability. Also, consider checking to see if your health insurance covers the cost of noninvasive prenatal testing. Cell-free DNA testing is also referred to as noninvasive prenatal testing.
Who Should Have a Cell-Free DNA Test?
Because older age increases chances of genetic disorders, all pregnant women over age 35 are offered prenatal DNA testing, as well as women with a family history of a child with a genetic condition, women whose ultrasound indicates an abnormality such as Down syndrome, and women with abnormal blood screens.
Advantages of Cell-Free DNA Testing?
Cell-free DNA testing was developed in 1997 after scientists discovered that fetal DNA appeared in the mother’s blood, making it possible for a simple blood draw to test for genetic disorders. Previously, amniocentesis was necessary to draw amniotic fluid cells from around the fetus to obtain its DNA. One in 200 pregnancies involve genetic disorders and age increases those chances, with a 40-year-old woman facing a 1 in 40 risk. Some genetic disorders are catastrophic such as Trisomy 13 or 18, in which an extra copy of chromosome number 13 or 18 means the baby is not likely to survive.
Forewarned of such issues, a woman can plan for her Down syndrome (Trisomy 21) child’s upbringing. Women may also consider terminating the pregnancy if it involves Trisomy 13, 18 or 21.
Though results of the cell-free DNA test are highly accurate, women who receive a positive test result are advised to undergo amniocentesis or chorionic villus sampling, which are slightly more accurate and test for all 46 chromosomes. Current cell-free fetal DNA testing only detects eight chromosome problems, including sex chromosome issues such as Turner syndrome.
However, cell-free fetal DNA testing is advancing rapidly and has the potential to detect issues in all 46 chromosomes.
The American College of Obstetricians and Gynecologists and the National Society of Genetic Counselors support cell-free DNA testing as an option for women with pregnancies at elevated risk for certain chromosomal abnormalities.
Learn more about Noninvasive Prenatal Testing/Noninvasive Prenatal Diagnosis: