Non-Invasive Prenatal Testing (NIPT): Should You Get It?

Non-invasive prenatal testing (NIPT) is a scan that can give you important information about your baby’s health and highlight any genetic issues early on. While it’s an optional test, many doctors advise getting it so you can make informed decisions regarding your baby’s well-being.

Read on to learn what NIPT is, what it screens for, and what its limitations are.

NIPT is a blood test that analyzes cell-free DNA (cfDNA) fragments circulating in your bloodstream, which include DNA shed from your placenta. By examining this cfDNA, the test can identify the likelihood of your baby developing certain chromosomal abnormalities.

You can get NIPT when you’re around 10 weeks pregnant. It has an advantage over invasive procedures like chorionic villus sampling (CVS) and amniocentesis because it poses no risk to your baby. 1

Many doctors use NIPT alongside other screening tests during the first trimester, such as nuchal translucency (NT). This is a type of pregnancy ultrasound that analyzes fluid on the back of your baby’s neck to determine whether your baby has genetic abnormalities, congenital heart defects, or skeletal problems. 2

NIPT primarily screens for common chromosomal disorders. These include:

• Trisomy 21: This is an extra copy of chromosome 21. This extra chromosome causes Down syndrome. Children with Down syndrome have issues with learning and talking, and often have congenital anomalies in the bowels or heart, among other things. 3
• Trisomy 18: An extra chromosome 18 causes Edwards syndrome. This syndrome is associated with significant intellectual problems and developmental issues, including in the limbs, heart, and brain. 4
• Trisomy 13: Patau syndrome is caused by an extra copy of chromosome 13. Patau causes a number of conditions, ranging from difficulties at birth, such as breathing and hearing problems, to severe intellectual disability, seizures, and life-limiting issues that affect the heart, brain, and spinal cord. 5
• Trisomy 16: This rare condition happens when cells have 3 copies of chromosome 16 instead of 2. It causes issues like heart defects, slowed growth, and developmental delays in babies during gestation. Unfortunately, most babies born with trisomy 16 die shortly after birth. 6
• Trisomy 22: Also known as mosaic trisomy 22, this is another rare condition characterized by cells having 3 copies of chromosome 22 instead of 2. It can cause your baby to be born with growth and cognitive delays, uneven development of the 2 sides of her body (hemidystrophy), and other physical abnormalities. 7
• Triploidy: This condition causes your baby to have 69 chromosomes instead of 46. It causes various congenital growth abnormalities in babies and often results in miscarriage. Thankfully, it’s also very rare. 8

What else can NIPT tell you?

Many NIPT tests can also screen for sex chromosome aneuploidies (an abnormal number of sex chromosomes), such as Turner syndrome and Klinefelter syndrome, and other conditions like microdeletion syndromes (conditions stemming from small deletions of contiguous genes). 9

In addition, NIPT can sometimes also determine whether or not you need a RhoGAM shot. This will protect your baby in case your Rh factor is different from hers, which could cause your body’s antibodies to attack her. 10

Note that the accuracy of NIPT varies depending on the disorder it is trying to detect. 11

Can you learn your baby’s sex through NIPT?

As an added bonus, NIPT can also tell you whether you’re having a boy or a girl. If you’d rather keep it a surprise, let your doctor know before getting the test. 12

Previously, NIPT was primarily recommended for women considered at high risk of having pregnancies with chromosomal abnormalities. Risk factors for this include:

• Being 35 or older by the time you give birth
• Having a previous pregnancy affected by a chromosomal abnormality
• A family history of chromosomal abnormalities
• Detecting abnormalities during a previous ultrasound

However, the American College of Obstetricians and Gynecologists (ACOG) now recommends that all pregnant women, regardless of age or risk factors, be offered NIPT as a screening option. 13

During the procedure, your doctor will draw a blood sample from a vein in your arm and send it to a laboratory for analysis. The procedure itself isn’t painful, although if you’re not a fan of needles, it can be a little uncomfortable. 12

It usually takes around 2 weeks to get the results. 12 Your doctor will then schedule an appointment with you to go over the results. You’ll usually get separate results for each condition your doctor screens for.

NIPT’s detection rate is upwards of 99% when screening for Down syndrome (trisomy 21). It tends to have a comparable detection rate for Edwards and Patau syndromes, aka trisomy 18 and 13 (96%–100%).

That being said, NIPT is a screening test, not a diagnostic test. A positive result only means that your baby has an increased risk of having a chromosomal disorder. You’ll need actual diagnostic tests to confirm whether she actually has a problem.

Similarly, a negative result does not conclusively rule out the presence of a chromosomal disorder, although it comes close (as the test is upwards of 99.9% accurate).

Can you get false positive and false negative results with NIPT?

While NIPT is generally accurate, it’s not perfect. False positive and false negative results are possible.

False positives are more common than false negatives, with one study finding that 47% of initial positive findings on NIPTs turned out to be false positives. 14 The rate is so high—in spite of the NIPT’s overall accuracy—because the disorders the NIPT screens for are relatively uncommon.

As for false negatives, they can happen if you don’t have enough fetal DNA in your blood to get accurate results.

How fetal fraction affects the NIPT’s accuracy

The fetal fraction is how much cfDNA in your blood comes from the placenta. NIPT is generally administered if your fetal fraction is 4% or more, which happens when you are 10 weeks pregnant.

If your fetal fraction is too low, it can lead to a false negative. 11

It’s also possible to have a low fetal fraction due to: 1

• Maternal obesity
• Certain medications (e.g., blood thinners)
• Certain autoimmune conditions

Regardless of the potential cause, if you have a , your doctor may ask you to test again at a later date. 12

What else affects the accuracy of NIPT?

In addition to being obese and being less than 10 weeks pregnant, several other factors can affect how accurate your results are, such as: 12

• Carrying multiples (twins or more)
• Using a donor egg
• Having certain maternal health conditions

In different ways and for different reasons, all of these can affect the proportion of fetal DNA present in your bloodstream, complicating the test.

Follow up with your OB if your NIPT results point to a high risk of a chromosomal abnormality. Your doctor will confirm a positive NIPT result with a different diagnostic test that can analyze your baby’s chromosomes.

Your doctor may suggest:

• Chorionic villus sampling (CVS): This involves taking a small sample of cells from the placenta. You’ll typically take the test when you are between 10 and 13 weeks pregnant. 15
• Amniocentesis: During amniocentesis, your doctor will take a small amount of amniotic fluid, which contains fetal cells. They’ll usually recommend this test once you’re past week 16 of your pregnancy. 16

The cost of NIPT can vary widely, ranging from several hundred to several thousand dollars, depending on your insurance coverage.

You can always call your insurance provider to ask if your plan covers NIPT screening and what you might pay in out-of-pocket costs or co-pay charges. Some laboratories also offer payment plans to offset the expense if the procedure is out of coverage.

There are slight differences between the various NIPT screenings offered on the market—talk to your OB so you can take the test that’s most appropriate for you. Factors to consider include your age, weight, whether you used an egg donor, and what specific conditions the test screens for.

While ACOG recommends that all pregnant women be offered NIPT, it’s a personal choice.

Before you decide whether NIPT is right for you, have an open and honest conversation with your doctor. They can also put you in touch with a genetic counselor who can explain in more detail what a positive result may mean for you.