What Is Non-Invasive Prenatal Testing?
Non-invasive prenatal test (NIPT) is a prenatal genetic test that screens for birth defects or inherited disease if any. Other names for this test are cell-free fetal DNA in the maternal circulation or fetal DNA testing.
Non-invasive prenatal test (NIPT) is a simple blood test performed that analyzes the baby’s DNA and detects the baby’s risk of genetic disorders, including Down syndrome. NIPT test, however, cannot for sure determine whether you are at an increased risk of giving birth to a baby with genetic disorder.
The result of the Non-invasive prenatal test (NIPT) helps the doctor decide whether to go ahead with the other test like chorionic villus sampling (CVS) or amniocentesis (Amnio). Both these tests give a 100% certainty whether a baby has a chromosomal abnormality or not.
However, these are a bit invasive and might increase the risk of miscarriage.
How Is Non-Invasive Prenatal Testing Done?
Non-invasive prenatal test (NIPT) involves quick drawing blood with a needle and is safe for the mother and the baby.
The sample is then sent to the lab, where the technician looks for the cfDNA in the blood for the signs of abnormalities.
After the result of the test is obtained the doctor compares it with the results of the first-trimester ultrasound to determine further tests if needed.
When is the Non-Invasive Prenatal Testing Performed?
The non-invasive prenatal test can be performed any time after 9 weeks of pregnancy, which is early than any other prenatal screening or diagnostic tests.
Other tests such as nuchal translucency are done between 11-13 weeks, CVS is done at 10-13 weeks, the quad screen is done at 14-22 weeks, and amniocentesis is performed between 16 and18 weeks and sometimes early as 13-14 weeks and as late as 23rd or 24th week.
How Long Does It Take To Get The Test Result Of Non-Invasive Prenatal Testing?
The Non-invasive prenatal test (NIPT) test takes about 8-14 days to get the result. In very few pregnancies the test is unable to give any result and a repeat of the test would be recommended.
Why is Non-Invasive Prenatal Testing Performed?
NIPT is performed to test for the common chromosomal disorders such as:
- Trisomy 21 (Down syndrome): A chromosomal condition associated with mild to moderate intellectual disability, weak muscle tone in infant, and a change in characteristic appearance. The children born with Down syndrome have a higher chance to be born with a physical birth defect such as intestinal problems and a heart defect.
- Trisomy 18 (Edward syndrome) and Trisomy 13 (Patau syndrome): These are two different chromosomal abnormalities that are associated with disability and medical problem problems. In both conditions survival beyond one year of life is uncommon.
- Sex chromosome disorders: In this, there is a difference in the number of sex chromosomes. The most common conditions are Turner syndrome, Klinefelter syndrome, Triple X syndrome, and XYY syndrome. There are less severe than Down syndrome but include learning disability and infertility.
Non-invasive prenatal test (NIPT) detects the baby’s Rh blood type and gender. Some researchers also think Non-invasive prenatal test (NIPT) can be a screening tool for moms, as well. A study done showed that the Non-invasive prenatal test (NIPT) results indicated genetic problems in the baby. But later it was found that the babies were not at risk but the results indicated an early onset of cancer in the mother.(1) Though, more research is needed before using this test for detecting cancer. But it can actually be an early diagnostic tool to detect early-stage cancer.
The Non-invasive prenatal test (NIPT) test is recommended for women at a higher risk of carrying a baby with chromosomal abnormality which includes the females:
- Pregnant at 35 years or above
- Has given birth to a child previously, with a genetic disorder
- Has a family history of any of the above conditions
- Or those who are concerned about the result of any other prenatal test
Non-invasive prenatal testing has drastically reduced the incidence of children with chromosomal abnormality to older mothers.(2)