Prenatal Screening – NIPTS
Did you know that pieces of your baby’s DNA circulate in your bloodstream? Noninvasive prenatal testing (NIPT) involves a simple blood screening that analyzes that DNA (it’s called cell-free DNA, or cfDNA) to pinpoint baby’s risk for a number of genetic disorders including Down syndrome. NIPT is a screening, which means it’s not “diagnostic” but tells you the likelihood of your baby having a disorder. But even though it can’t tell for sure whether your baby has a genetic abnormality, it is highly accurate. The results can help you and your doctor decide next steps, including whether invasive diagnostic tests — which are even more precise but slightly increase the chance of miscarriage — are worth the risk.
HOW NIPT IS DONE
Because an NIPT involves only a quick blood draw with a needle and syringe, all you’ll need to do is offer up your arm at the doctor’s office or a lab — totally safe for you and your baby. Your sample is then sent off to a lab, where a technician will look at the cfDNA in your blood for signs of abnormalities.
Once the results of your NIPT are back, your doctor will likely pair them with the results of your first-trimester ultrasound or nuchal translucency screening to determine whether more testing is needed. If it’s positive, your doctor may recommend following up with amniocentesis or CVS to confirm the result and check for other problems NIPTs can’t detect.
WHAT IT SCREENS FOR
Four companies currently offer noninvasive prenatal testing, and they all screen for the most common chromosomal disorders: trisomy 21 (Down syndrome), trisomy 18 (Edwards syndrome), and trisomy 13 (Patau syndrome); some also screen for other abnormalities including triploidy and microdeletion. It’s worth noting that while some brands differentiate between maternal and fetal cfDNA others do not (which means they’re less accurate), so you might want to ask your practitioner which type of test she uses.
NIPT also detects your baby’s Rh blood type and gender, so be sure to let your doctor know if you want to be surprised on delivery day!
Since the tests looks at a sample of your blood, some researchers think it may eventually also be a screening tool for moms, too. In one new study, some NIPT results indicated a baby was at risk for a genetic problem. But later it was clear the baby was not at risk and the results were actually indicating the early onset of a cancer in the mom. The findings need further research before practitioners begin using the tests for this purpose — but because the test could potentially detect early-stage cancer, before symptoms are apparent, it could help women get further diagnostic tests and care earlier, when it’s more effective.
WHEN IT’S DONE
NIPT can be performed any time after 9 weeks into your pregnancy — earlier than any other prenatal screening or diagnostic test. In comparison, nuchal translucency screening is done between weeks 11 to 12; CVS is done at 10 to 12 weeks; quad screening is completed between weeks 15 and 22; and amniocentesis is usually performed between weeks 15 and 20.
THE ACCURACY OF NIPT
Research suggests that NIPTs create fewer false alarms than standard first-trimester blood screenings (like first trimester blood work or quad screening) that measure hormones and special proteins in mom’s blood. Other research has shown that NIPTs are more accurate than those same standard screenings in predicting the risk of Down syndrome (NIPTs are 99 percent accurate) along with Edwards syndrome — though the American College of Obstetricians and Gynecologists (ACOG) says NIPT needs to be further evaluated before it will recommend the screening for all pregnant women.
WHO IT’S FOR
In the past, NIPTs were only recommended for women at high risk for carrying a baby with a chromosomal abnormality — like moms-to-be who are 35 or older, previously had a child with a genetic disorder or have a family history of these conditions — or if there was a concern about the result of another prenatal test.
ACOG now recommends that doctors discuss all screening options with all pregnant women — regardless of age or risk — to figure out which one, if any, is most appropriate. The decision is a personal one, and this counseling phase is important. Just because a test was right for a friend doesn’t mean it’s right for you. Be sure to ask your health care provider to spend some time going over all your choices. Considering how quickly the science is evolving, the guidelines about which screenings are best for you may change.
WHAT ELSE YOU NEED TO KNOW
Before you go through with an NIPT, double-check with your insurance company to find out if it’s fully covered — and if not, what it will cost you. Also, while getting this test done is far from scary (unless you really hate needles), you may be nervous about seeing the results. If this is the case for you, consider talking to your doctor or to a genetics counselor about what positive test results could mean for you and your baby. For many parents, knowing as much as possible as soon as possible is better. Finding out about potential conditions early on allows you to prepare for a special needs baby and make plans to deliver at a facility that can better address your and your baby’s health needs right away.