NIPT Non-Invasive Prenatal Screening Test

What is Non-invasive Prenatal Screening Test
The Non-invasive prenatal test (NIPT –NIP’ TEE) is an optional blood test that can be given as early as 10 weeks of pregnancy to screen for developing genetic abnormalities. The test screens for the most common chromosomal conditions that can affect your baby’s health. It gives parents-to-be a choice to obtain important information about the health of their developing baby in the first trimester, with no risk to their pregnancy. Test results are first reported back to your doctor and next shared with you usually within 14 business days
If you are currently pregnant, talk to your fertility specialist or call our fertility team +65 6723 7889 about booking in for an NIPT appointment.
Getting an NIPT screening test, how is it done?
During your doctor visit with one of our specialists, a sample of your blood is drawn for the NIPT screening test. The blood work is sent to the lab where analysis of material (DNA) from you and your baby is tested. Through advanced technology and ‘sequencing’ the test analyses millions of DNA fragments per sample and accurately counts the number of chromosomes present. It then uses a special calculation method to determine if your baby has too many or too few copies of these chromosomes.
What does NIPT screen?
NIPT tests assess the likelihood that your baby has certain genetic disorders caused by deletions, insertions, or duplications of chromosomes or large sections of chromosomes, called aneuploidy (AN-yoo-PLOY-dee).
- Taking a page from biology, chromosomes usually come in pairs. Normal embryonic cells have 23 pairs of chromosomes – 46 chromosomes in total. NIPT looks for too few or too many copies of these chromosomes. Missing or extra chromosomes can cause intellectual or physical disabilities, with different levels of severity.
- These disorders include Trisomy 21 (Down Syndrome), Trisomy 18 (Edwards Syndrome), Trisomy 13 (Patau Syndrome), and some sex chromosome conditions. Some tests will also screen for other genetic disorders caused by certain gene variants or single gene mutations.
- The test evaluates the blood’s cell free DNA (cfDNA), which is fragments of DNA that circulates in your blood outside of the cells. In a pregnant woman, her cfDNA will contain DNA from the placenta, which should be identical to the DNA of the growing fetus.
How Accurate is the NIPT?
It is important to note that NIPT is a screening test, not a diagnostic test. In a screening test, analysis provides a risk assessment, while diagnostic tests provide yes or no answers in terms of whether a disorder is present. However, NIPT is highly accurate, detecting 97-99% of aneuploidies before delivery. False positives are slightly more common for more rare conditions including single cell mutations.
Additionally, NIPT analyzes DNA originating from the placenta and not from the developing foetus. Although the placental DNA is highly indicative of the foetal DNA, it is not guaranteed to be identical, and discrepancies between the baby’s DNA and the placenta can occur.
If the results of the NIPT indicate a high risk of any of these conditions, an additional test called amniocentesis can be performed if the patient chooses. This is a diagnostic test, rather than a screening test, where a small sample of amniotic fluid is taken from the uterus through the belly and analyzed for genetic disorders.
Should I do a NIPT, is it right for me?
The choice to undergo any prenatal genetic testing is entirely yours, and it should reflect your personal values and needs. What makes NIPT a unique test is that it’s non-invasive and poses no risk to your developing fetus.
Your physician or fertility specialist can help you to decide on the best course of action for your pregnancy, including whether or not you should take the NIPT. Factors to consider include:
- At what point or where you are at in the term of your pregnancy, your age, and your family history.
- Some couples and parents may choose not to undergo any genetic testing and feel comfortable with their risk of having a baby with a genetic disorder. While other parents prefer to be given all possible information to be prepared for their pregnancy journey.
Our patients have access to experienced prenatal genetic counselors.
Ultimately, the decision should be thoroughly considered and discussed with your doctor. Speak to our fertility team to learn more: info.sg@monashivf.com or reach out to us: +65 6723 7889.