Top Ten Questions Around NIPT or Non-Invasive Prenatal Testing

1. What is NIPT

Non-invasive prenatal testing (NIPT) is a blood test performed during pregnancy that identifies whether your baby has a higher chance of having certain genetic or chromosomal conditions, such as Down syndrome. NIPT can also identify your baby’s genetic sex, should you choose to know this during pregnancy. The test is considered non-invasive because it requires drawing a simple blood sample from the pregnant woman and therefore does not pose any risk to the developing baby.

2. How does NIPT work?

NIPT detects small fragments of DNA, known as cell-free DNA, in the pregnant mother’s bloodstream.  Most of these DNA fragments will be from the mother herself, but a proportion will come from the pregnancy. By analysing these DNA fragments it is possible to determine if the foetus has a high or low risk for certain genetic conditions or syndromes.

3. What can NIPT detect or tell me about my pregnancy?

NIPT is a screening test that can tell you if your unborn baby has a high or low risk of having certain underlying genetic conditions or syndromes. Screening tests, like NIPT, cannot diagnose genetic conditions, therefore results should be confirmed with other diagnostic tests, such as amniocentesis. NIPT can also detect the genetic sex of your baby if you choose to know this. NIPT cannot detect structural abnormalities in your baby, such as a heart defect, cleft lip or clubfoot. NIPT can only screen for the specific genetic conditions covered by the NIPT option selected.

4. What are the main benefits of NIPT in terms of testing?

• High Accuracy: NIPT has been shown to have a high accuracy rate in detecting common chromosomal abnormalities, such as Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), and Patau syndrome (trisomy 13).
• Non-Invasive: NIPT is a non-invasive test that can be performed by analysing a maternal blood sample. It does not pose any risk of miscarriage or harm to the foetus since it does not involve any invasive procedures, such as amniocentesis or chorionic villus sampling (CVS).
• Early Detection: NIPT can be performed as early as 9 weeks into the pregnancy, providing early information about the risk of chromosomal abnormalities. Early detection allows parents to have more time for decision-making and to consider further diagnostic tests if needed.
• Reduced Need for Invasive Testing: By providing accurate information about the risk of chromosomal abnormalities, NIPT can help reduce the need for invasive testing procedures like amniocentesis or CVS. These invasive tests carry a small risk of complications, including miscarriage, making NIPT a safer alternative for many expectant parents.
• Peace of Mind: NIPT offers expectant parents reassurance and peace of mind. It can provide valuable information about the likelihood of chromosomal abnormalities, which can help parents prepare emotionally, seek appropriate medical care, and plan for the future.
• Additional Information: In addition to detecting common chromosomal abnormalities, NIPT can also provide information about foetal sex and certain rare genetic conditions caused by specific gene mutations. This information can be helpful for families who want to be prepared or need to make informed decisions regarding their pregnancy.
• Increasing Availability: NIPT has become more widely available in recent years, making it accessible to a larger number of expectant parents. It can be offered to women of all ages and is particularly recommended for women who are at higher risk of having a baby with chromosomal abnormalities, such as those who are older or have a family history of genetic disorders.

5. What genetic conditions can NIPT screen for?

NIPT is primarily used to detect common aneuploidies, these are genetic conditions caused by extra or missing chromosomes. Most people have a standard complement of 46 chromosomes. Examples of conditions detectable by NIPT include Down syndrome (extra chromosome 21), Patau syndrome (extra chromosome 13) and Edwards syndrome (extra chromosome 18). Since NIPT can also evaluate the sex chromosomes, sex chromosome aneuploidies, such as Turner syndrome (missing X chromosome in a female) or Klinefelter syndrome (extra X chromosome in a male) can also be detected. NIPT can also be used to screen for smaller imbalances in some or all of the chromosomes, called microdeletions or microduplications. It is important to know that NIPT cannot detect all possible genetic conditions or syndromes.

6. When is the best time to have an NIPT test?

NIPT can be done as early as nine weeks into your pregnancy. While there is no specific cut-off time for NIPT, the greatest benefit of NIPT is in knowing your risks very early into your pregnancy. Most women will therefore have NIPT in their first trimester or sometimes the second trimester of pregnancy. NIPT can only be performed during pregnancy.

7. How do I know if NIPT is right for me?

The decision to undergo NIPT or any other prenatal screening tests should be made in consultation with a healthcare provider, who can assess the individual circumstances and recommend the most appropriate course of action.

NIPT (Non-Invasive Prenatal Testing) is generally recommended for pregnant women who have an increased risk of having a baby with chromosomal abnormalities. Here are some situations when it is commonly recommended:

• Maternal Age: Advanced maternal age is a well-known risk factor for chromosomal abnormalities, particularly Down syndrome. NIPT is often recommended for women who are 35 years old or older as the risk of chromosomal abnormalities increases with age. Chromosomal abnormalities can however occur in women of any age.
• Abnormal screening results: If a pregnant woman undergoes other screening tests, such as first-trimester combined screening (which includes a blood test and an ultrasound), and the results indicate a higher risk for chromosomal abnormalities, NIPT may be recommended as a follow-up test to provide more accurate information.
• Previous pregnancy with chromosomal abnormality: If a woman has previously had a pregnancy with a chromosomal abnormality, such as Down syndrome, Edwards syndrome, or Patau syndrome, NIPT may be recommended for subsequent pregnancies to assess the risk.
• Family History: In cases where there is a known family history of certain genetic conditions or chromosomal abnormalities, NIPT may be recommended to assess the risk in the current pregnancy.
• Ultrasound Findings: In some instances, an ultrasound may reveal certain markers or indications that increase the risk of chromosomal abnormalities. In such cases, NIPT may be recommended to further evaluate the likelihood of these conditions.

With that in mind the guidelines from the American College of Obstetrics and Gynaecologists (ACOG) and American College of Medical Genetics and Genomics (ACMG) recommend that the option of NIPT is discussed with all pregnant women, regardless of maternal age or baseline risk.

8. What happens if NIPT indicates a high risk for a genetic condition in my baby?

It's important to note that NIPT is a screening test, and a positive result does not provide a definitive diagnosis of a chromosomal abnormality. If NIPT results indicate a high risk, further diagnostic testing, such as amniocentesis or chorionic villus sampling (CVS), may be recommended to confirm the diagnosis. Decisions about your pregnancy should never be made based on an NIPT result alone. Speaking to your gynaecologist, foetal-medicine specialist or genetic counsellor can further help clarify the implications of a high risk NIPT result and the options available to you.

9. What are the limitations of NIPT:

It's important to note that while NIPT is highly accurate, it is still considered a screening test and not a diagnostic test. In cases where NIPT results indicate a high risk of chromosomal abnormalities, further diagnostic testing, such as amniocentesis or CVS, may be recommended to confirm the diagnosis. NIPT can only screen for the specific genetic conditions covered by the NIPT option selected. A low risk result does not exclude the possibility of an underlying genetic condition or syndrome since NIPT cannot detect all possible genetic conditions or syndromes.  NIPT cannot detect structural abnormalities in your baby, such as a heart defect, cleft lip or clubfoot.

10. Who can I speak to if I want more information about NIPT or want a NIPT test

NIPT can only be ordered through a health care provider. You can discuss the option of NIPT with your gynaecologist during pregnancy. You can also visit Mediclinic Precise for more information