Non-invasive prenatal tests (NIPT) are a useful way for pregnant individuals to assess the risk of a chromosomal condition's occurrence in a fetus (not to be confused with diagnosing conditions themselves). They analyse cell-free DNA in a maternal blood sample to assess the risk of certain chromosomal abnormalities in the fetus. It primarily screens for the common chromosomal disorders of Down syndrome, Edwards syndrome, and Patau syndrome. Depending on the test used, NIPT may also screen for certain sex chromosome abnormalities and selected chromosomal microdeletions.

Key Takeaways

NIPT is a highly accurate prenatal screening test that can be performed from around 9 to 10 weeks of pregnancy using a maternal blood sample.
It screens for common chromosomal abnormalities, including Down syndrome, Edwards syndrome, and Patau syndrome, and may also assess additional chromosomal conditions depending on the test used.
NIPT is a screening test, not a diagnostic test. A high-risk result may require further testing, such as amniocentesis or chorionic villus sampling (CVS), for confirmation.

How Is NIPT Performed?

NIPT can be performed from 10 weeks of pregnancy onwards. The test involves taking a blood sample from the mother, which is then sent to a laboratory for analysis.

The blood sample contains small fragments of cell-free DNA (cfDNA) from both the mother and the placenta. By analysing this DNA, the laboratory can assess the likelihood of certain chromosomal abnormalities, including Down syndrome, Edwards syndrome, and Patau syndrome.

Results are typically available within one to two weeks, depending on the laboratory. If the results indicate a higher risk of a chromosomal abnormality, your doctor may recommend further diagnostic testing to confirm the findings.

Should You Get an NIPT for Your Pregnancy?

NIPT is a low-risk method of assessing the risk of your fetus having various chromosomal abnormalities, which would then result in a variety of disorders. It informs you of whether your fetus might have certain chromosomal disorders, the most common being:

Down syndrome (Trisomy 21)
Edwards syndrome (Trisomy 18)
Patau syndrome (Trisomy 13)

Other conditions include those related to sex chromosomes, such as Turner syndrome and Klinefelter syndrome.

Unlike other methods of screening that can be more invasive, NIPT poses no risk of miscarriage. NIPT has a detection rate of more than 99% for Down syndrome and a low false positive rate, making it one of the most accurate prenatal screening tests currently available. It can help determine whether further diagnostic testing is needed to confirm the findings. In the same vein, it reduces the number of patients requiring invasive tests, such as amniocentesis or chorionic villus sampling, which pose the risk of miscarriage.

While NIPT is suitable for all pregnant women, it may be particularly beneficial for those at a higher risk of carrying a baby with a chromosomal abnormality. This includes women who:

Are aged 35 years or above
Have received a high-risk result from first trimester screening (FTS)
Have had a previous pregnancy affected by Down syndrome or another chromosomal abnormality

What Are the Benefits and Limitations of Getting an NIPT?

One should take into consideration the various benefits and limitations involved in getting an NIPT. While it is a highly accurate low-risk screening, it is important to be well-informed about both sides.

Benefits

Early Detection: Screenings can be done as early as the 10th week of pregnancy, detecting any health issues of the fetus sufficiently early. This information can help expectant parents make informed decisions about further testing, pregnancy care, and preparation for their baby's needs.

Reduced Risk: As a non-invasive screening method, there is little to no risk for the mother and fetus.

Limitations

Test Failure: Test failure may occur because of factors such as a low foetal fraction. Interpretation may also be more complex in twin or higher-order multiple pregnancies.

Not All Conditions Detected: NIPT screens for selected chromosomal abnormalities and cannot detect all genetic or congenital conditions.

Monitor Your Fetus's Health with Dr Christopher Ng

Pregnancy can be an exciting journey, but the uncertainty that comes with it can sometimes feel difficult to navigate. NIPT can help to assuage your concerns and give critical information regarding your fetus' health that will inform you how to prepare for whatever comes next.

At GynaeMD Women's & Rejuvenation Clinic, obstetrician and gynaecologist Dr Christopher Ng can guide you with personalised and specific care in a warm, welcoming environment. With over 30 years of experience as an OBGYN, Dr Ng will attend to you with sensitivity and medical expertise. If you are ready to take the next step for both your baby and your family, schedule a consultation with us today.

FAQs About NIPT During Pregnancy

How accurate is NIPT compared to other prenatal screening tests?

NIPT is significantly more accurate than first trimester screening (FTS). It is more sensitive and specific, with lower false positive rates, particularly in the detection of Down syndrome. The accuracy varies between conditions, with the more common ones detected with greater accuracy.

Can NIPT tell me the sex of my foetus?

NIPT can often predict the sex of the baby by analysing the presence or absence of Y chromosome material in the maternal bloodstream.

Is NIPT covered by insurance in Singapore?

Most insurers do not cover NIPT as it is generally considered an optional test. However, coverage may be available in certain circumstances, such as when a pregnancy is considered high risk. As coverage varies between insurers and insurance plans, patients should check with their insurance provider to understand their eligibility and benefits.

Do You Need NIPT During Pregnancy? A Simple Guide