For anyone having a baby, no matter their age or genetic makeup, there is a natural worry of birth defects. No one wants to hear the devastating news that their baby’s survival rate of a genetic disorder is low. Ninety-six percent of women with a positive test on the standard screen don’t end up having a child with Down syndrome.
In order to be truly sure of a diagnosis, women with a positive test undergo more invasive testing such as amniocentesis or chorionic villus sampling. Not only are these tests more invasive, they carry with them a risk of miscarriage.
When you are pregnant, a doctor will offer the option of getting an amniocentesis but most women opt not to have it because of the risk of miscarriage. In most cases, they only get it if their blood test showed a positive result. It’s a stressful risk and involves weeks of agonizing over waiting for results to either find out the blood test was right or that it was wrong and your growing baby is healthy. No one wants to deal with that.
But there is a new non-invasive blood test with a higher accuracy rate called the cell free DNA test (cfDNA). It looks at small amounts of actual fetal DNA in mom’s blood. It can be done as early as the 10th week of pregnancy. Cell-free DNA testing is thought to detect greater than 99 percent of all Down syndrome pregnancies and greater than 98 percent of all trisomy 18 pregnancies. It detects about 65 percent of all trisomy 13 pregnancies.
Researchers performed the test on nearly 2,000 pregnant women and found that the rate of false positives with this new test was 10 times lower than with standard screening measures, which are done later in the pregnancy.
If you were screened positive with cfDNA test, there was a 45 percent chance that your fetus had Down syndrome, and if you had a standard test only a 4 percent chance that the fetus had Down syndrome. It is recommended for women who are at high risk for having a baby with birth defects and a non-invasive option for those who get a positive on the standard screening.
The cfDNA test provides more accurate information at an earlier stage of pregnancy and it’s ultimately up to the parents what they do with that information. There is a catch to this test though. The American College of Obstetrics and Gynecology has yet to update recommendations on screening which means this test is not likely to be covered by insurance.
This advanced test also totes a hefty price tag. Four companies offer cell free DNA testing: Verifi, MaterniT21, Harmony, and Panorama. A single test generally costs anywhere from $795 to $2,000, compared to standard screens that are usually around $200-250. And until further research is done, it remains unlikely that this will be covered by standard insurance plans.
Physicians are hopeful that this could represent the future of prenatal testing and almost eliminate the high rate of false positives that standard screening provides. Right now, you would not be covered by insurance for this test but if you are at high risk for chromosomal defects, the out of pocket cost would likely feel worth every penny for the peace of mind during your pregnancy.