NIPT
Non-Invasive Prenatal Testing (NIPT) is a screening test performed during pregnancy to assess the risk of certain chromosomal abnormalities in the fetus.
What is NIPT?
Non-Invasive Prenatal Testing (NIPT) is a screening test performed during pregnancy to assess the risk of certain chromosomal abnormalities in the fetus.
NIPT can be performed as early as the 10th week of pregnancy to analyse fragments of fetal DNA (genetic material) circulating in the mother’s blood. By examining this fetal DNA, the test can identify whether the baby has certain chromosomal abnormalities, such as Down syndrome.
What does NIPT screen for?
NIPT can screen for:
• Down syndrome (Trisomy 21)
• Edwards syndrome (Trisomy 18)
• Patau syndrome (Trisomy 13)
• Sex chromosome abnormalities (e.g., Turner syndrome, Klinefelter syndrome)
• Some genetic abnormalities
• The sex of the fetus
When can NIPT be performed?
- NIPT can be done as early as the 10th week of pregnancy.
What are the advantages of NIPT?
• Non-invasive testing: NIPT only requires a blood sample from the mother and presents no risk to the fetus.
• Early insights: NIPT can be performed as early as 10 weeks into a pregnancy, providing early and accurate insights into the health of the fetus.
• Highly accurate: NIPT has a high detection rate for common chromosomal abnormalities such as Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), and Patau syndrome (trisomy 13).
How is NIPT screening performed?
1. Blood Sample: A small blood sample is taken from the mother’s arm.
2. DNA Analysis: The sample is sent to a lab to analyse the fetus’ DNA.
3. Results: Results are usually available in one week.
4. Repeat test: On rare occasions, you may be asked to repeat the test if the fetal DNA is insufficient.
How accurate is NIPT?
NIPT is significantly more accurate than previous screening tests for the detection of Down syndrome. It will detect over 99% of Down syndrome cases. However, it is important to note that NIPT isn’t foolproof. It has a small false positive rate of 0.3%, meaning only one in 350 women will erroneously receive a positive result when the fetus is actually healthy.
In the event of a positive result, further testing will be done to get a definitive result.
IS NIPT suitable for all pregnant women?
NIPT is generally recommended for most pregnant women. However, there are certain situations where it might not be suitable:
1. Multiple Pregnancies: NIPT is suitable for twin pregnancies, however, it is not recommended for women pregnant with three or more babies.
2. High BMI: Women with a very high body mass index (BMI) may have a slightly higher risk of the test not providing conclusive results due to lower levels of fetal DNA in the bloodstream2.
3. Recent Blood Transfusion or Transplant: Women who have had a recent blood transfusion or organ transplant may have foreign DNA in their blood, potentially affecting the accuracy of the test results.
4. Cancer Diagnosis: Women with a current or recent cancer diagnosis may have altered DNA in their blood, which can interfere with the test results.
Please discuss any specific health conditions you have with your doctor to determine if NIPT is the right choice for you. They can provide personalised advice based on your medical history and pregnancy.
Understanding the Results
• Low-Risk Result: Indicates a low risk of the fetus having the screened chromosomal abnormalities.
• High-Risk Result: Indicates a higher risk of the fetus having a chromosomal abnormality. Further diagnostic testing, such as amniocentesis or chorionic villus sampling (CVS), is recommended to confirm the result.
Does the NIPT replace my first trimester (nuchal translucency) ultrasound examination?
No, the NIPT does not replace your first-trimester scan. The scan provides important information about your baby’s development, including confirming the pregnancy’s gestational age, assessing the overall development of the fetus, and screening for additional chromosomal anomalies.
It’s important to remember that NIPT is a screening test, not a diagnostic test. This means that it assesses the risk but does not provide a definitive diagnosis.
When should I expect my results back?
Test results are usually available in approximately one week. However, in some cases, it may take longer.
Discuss with your Healthcare Provider
Discussing NIPT with your healthcare provider is important to determine if it’s the right choice for you. They can provide detailed information based on your health and pregnancy.
