What Does NIPT Test For?

Learn what NIPT tests for in 2026 — including chromosomal conditions like Down syndrome. US guide to non-invasive prenatal testing and how to order a panel.

Non-invasive prenatal testing (NIPT) screens for common chromosomal abnormalities by analyzing cell-free DNA (cfDNA) fragments from the placenta that circulate in a pregnant person's blood. As of 2026, NIPT is the most sensitive screening option for conditions such as Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), and Patau syndrome (trisomy 13). It also can detect sex chromosome aneuploidies and, with expanded panels, certain microdeletion syndromes. NIPT is a screening test, not a diagnostic one; abnormal results require confirmation via chorionic villus sampling or amniocentesis. This guide explains exactly what NIPT tests for, how it compares to other prenatal screenings, and how to proceed if you're considering it.

How NIPT Works

NIPT analyzes cell-free DNA that naturally enters the maternal bloodstream from the placenta. A simple blood draw is performed after 10 weeks of pregnancy. The lab sequences the cfDNA to count the relative amounts of each chromosome. An extra copy (trisomy) appears as a slight increase in that chromosome's cfDNA fraction. The test also reports the fetal fraction — the proportion of cfDNA that comes from the placenta — which must be above a certain threshold (typically 4%) for reliable results. Low fetal fraction can lead to a no-call result and may prompt a redraw or alternative testing.

What NIPT Screens For

Common Trisomies

Trisomy 21 (Down syndrome) — detection rate >99%, false-positive rate <0.1%
Trisomy 18 (Edwards syndrome) — detection rate ~97%
Trisomy 13 (Patau syndrome) — detection rate ~90%

Sex Chromosome Aneuploidies

Many NIPT panels include analysis of the X and Y chromosomes to detect conditions such as Turner syndrome (45,X), Klinefelter syndrome (47,XXY), Triple X syndrome (47,XXX), and Jacobsen syndrome (47,XYY). These are reported with slightly lower accuracy than the common trisomies but still provide valuable early information.

Optional Microdeletion Syndromes

Some expanded NIPT panels screen for microdeletions like 22q11.2 deletion (DiGeorge syndrome), 1p36 deletion, Prader-Willi/Angelman syndromes, and others. These are rare but serious; detection rates vary by laboratory and condition. Discuss with a genetic counselor whether an expanded panel is right for you.

Comparison of Prenatal Screening Options (2026)

Test Type	Timing	What It Screens	Accuracy for T21	Invasive?
NIPT (cell-free DNA)	10+ weeks	Trisomies 21,18,13; sex aneuploidies; optional microdeletions	>99%	No
First-trimester screening (NT + blood)	11–14 weeks	Trisomies 21 & 18; neural tube defects	~85%	No
Quad screen	15–22 weeks	Trisomies 21 & 18; neural tube defects; Smith-Lemli-Opitz syndrome	~80%	No
Integrated screening	First + second trimester	Combined results from first-trimester and quad screen	~92%	No
Chorionic villus sampling (CVS)	10–13 weeks	Diagnostic for all chromosomes	99.9%	Yes
Amniocentesis	15–20 weeks	Diagnostic for all chromosomes	99.9%	Yes

What NIPT Does Not Test For

NIPT is not a comprehensive screen. It does not detect neural tube defects (spina bifida, anencephaly), abdominal wall defects, or most structural anomalies. Those require maternal serum alpha-fetoprotein (MSAFP) screening or detailed ultrasound. NIPT also does not screen for most single-gene disorders (e.g., cystic fibrosis, spinal muscular atrophy) — those are covered by carrier screening, which is a separate blood test. Some labs offer combined NIPT + carrier screening panels, but they remain distinct tests.

When to Consider NIPT

NIPT is offered to all pregnant individuals in the US, regardless of age or risk factors. The American College of Obstetricians and Gynecologists (ACOG) recommends that all patients be informed about NIPT as an option. It is especially valuable for those with advanced maternal age (≥35), a prior pregnancy with a chromosomal abnormality, or abnormal ultrasound findings. Because NIPT is a screening test, a positive result should always be followed by diagnostic testing (CVS or amniocentesis) and a consultation with a genetic counselor.

Frequently Asked Questions

Can NIPT determine the baby's sex?

Yes, NIPT can determine fetal sex by detecting Y chromosome sequences. This is often included automatically or can be requested. Accuracy for sex determination is >99% when fetal fraction is adequate.

How long does it take to get NIPT results?

Most labs return results within 7–10 business days from the time the blood sample is received. Some offer expedited options.

What if my NIPT result is “no-call” or “insufficient fetal fraction”?

A no-call result occurs when the fetal fraction is too low (common in early gestation or with higher maternal BMI). Your provider may recommend a redraw in 1–2 weeks or proceed directly to diagnostic testing or alternative screening.

Can NIPT be used for twin pregnancies?

Yes, NIPT is available for twin and higher-order multiples, though accuracy may be slightly lower than in singletons. Some labs require a separate algorithm. Discuss with your provider.

If you're ready to learn more about your options, you can order a comprehensive prenatal screening panel online that includes NIPT plus carrier screening for common genetic conditions. Results are typically delivered within 7–10 days, giving you early, actionable information to discuss with your healthcare team.