Your NIPT Blood Test
A simple guide to the screening blood test you may have early in pregnancy.
Early in pregnancy, you may be offered a blood test called NIPT. The full name is non-invasive prenatal testing. You may also hear it called the cell-free DNA test or the cfDNA test. This guide walks you through it step by step, before your test.
It takes about 5 minutes to read. Use the Next and Back buttons to move through it.
This test is your choice. This guide is here to help you understand what it can tell you, what it cannot, and what questions you may want to ask.
What this guide is built on
- American College of Obstetricians and Gynecologists' Committee on Practice Bulletins—Obstetrics, Committee on Genetics, and the Society for Maternal–Fetal Medicine. Screening for Fetal Chromosomal Abnormalities: ACOG Practice Bulletin, Number 226. Obstet Gynecol. 2020;136(4):e48–e69. doi:10.1097/AOG.0000000000004084. PMID 32804883 — the recommendation that this test be offered to all patients, the timing, the conditions it checks, and how the meaning of a result changes with age.
- American College of Obstetricians and Gynecologists. Prenatal Genetic Screening Tests. ACOG patient FAQ. — plain-language source on screening tests in pregnancy.
What is the NIPT test?
NIPT is a simple blood test. A nurse draws blood from your arm, just like many other blood tests. It is safe for you and your baby.
During pregnancy, tiny bits of DNA from the placenta (the organ that feeds your baby) float in your blood. The lab looks at these bits of DNA to learn about your baby's chromosomes — the tiny packages inside cells that hold our genes.
This test can be done from about 10 weeks of pregnancy onward. Doing it a bit later, rather than too early, helps make sure there is enough placental DNA in your blood for a clear answer.
You usually get your results in about one to two weeks. Your clinic will tell you how they share results.
What does it check for?
NIPT looks for the most common chromosome conditions. These happen when there is an extra copy of one chromosome.
- Down syndrome (also called trisomy 21) — the most common of the three.
- Trisomy 18 (Edwards syndrome).
- Trisomy 13 (Patau syndrome).
Many tests also look at the chromosomes that decide sex, so the test can often tell you your baby's sex if you want to know.
This test is offered to all pregnant patients, no matter your age. You can choose to have it, or choose not to. Your care team can help you decide what is right for you.
The most important idea
NIPT is a screening test. This is the key thing to understand before you take it.
A screening test tells you the chance that your baby has one of these conditions. It does not give a yes-or-no answer.
A diagnostic test gives a sure answer. The diagnostic tests in pregnancy are called CVS and amniocentesis. They take a small sample to check the baby's chromosomes for certain.
NIPT is the most accurate screening test we have for these three conditions. But it is still a screening test. That is why a result that shows a higher chance is always checked with a diagnostic test before anything is known for sure.
Your possible results
Tap each result below to see what it means. Your care team will always go over your own result with you.
This means the chance of these conditions is very low. Most people get this result, and it is reassuring.
It still cannot promise a perfectly healthy baby, because no test checks for everything. But for the conditions NIPT looks at, a low-chance result is a strong sign that they are unlikely.
This means the chance is higher than usual. It does not mean your baby definitely has the condition.
How likely a higher-chance result is to be correct depends on your age and on which condition. It tends to be more likely to be correct for older mothers and for Down syndrome, and less likely for younger mothers and for trisomy 13 and 18. This is exactly why a sure answer needs a diagnostic test.
If you get this result, your care team will offer you a diagnostic test (CVS or amniocentesis) and time to talk it through. You decide the next step.
Sometimes the test cannot give a clear answer. This often happens when there is not enough placental DNA in the blood sample, which can be more common very early in pregnancy.
If this happens, your care team may ask you to give another blood sample, or may talk with you about other options. A no-result is worth following up on, so do not skip the next step they suggest.
Finding out the sex
Because the test looks at chromosomes, it can often tell your baby's sex.
- If you want to know, you can ask your care team how and when they will share it.
- If you do not want to know, tell them before the test so they can leave it out.
There is no right or wrong choice here. It is fully up to you.
What this test does not do
It helps to know the limits, so the test fits into the bigger picture of your care.
- It does not check your baby's body parts, heart, or spine. That is the job of the anatomy ultrasound later in pregnancy.
- It does not find every genetic or health condition. It focuses mainly on the three common chromosome conditions.
- It is not a sure answer on its own. Only a diagnostic test (CVS or amniocentesis) can give that.
NIPT is one part of your pregnancy care. You will still be offered other tests and scans. Together, they give your care team a fuller picture.
Your questions
Tap any questions you may want to ask your care team. Then make your own list to print or keep.
Before you decide — a few reminders
- NIPT is a safe blood test, done from about 10 weeks on.
- It checks the chance of three common chromosome conditions.
- It is a screening test — it gives a chance, not a sure answer.
- A higher-chance result is checked with a diagnostic test before anything is known for sure.
- Most results show a low chance.
- Having the test is your choice.
It does not replace your clinician or midwife, and it is not for emergencies. For any question or concern about your pregnancy, call your clinician or midwife. If you feel you may need urgent help, contact your local emergency services.