Non-Invasive Prenatal Testing (NIPT) is a revolutionary prenatal screening technology that analyzes fetal cell-free DNA (cfDNA) in a pregnant woman’s blood to assess the risk of chromosomal abnormalities such as trisomy 21 (Down syndrome), trisomy 18 (Edwards syndrome), and trisomy 13 (Patau syndrome).
Unlike traditional invasive methods like amniocentesis, NIPT offers a safe, highly accurate, and non-invasive way for expecting parents to gain early insights into their baby’s genetic health.
📜 A Brief History of NIPT
The origins of NIPT date back to the 1990s, when researchers first discovered that fragments of fetal DNA (cfDNA) circulate in the mother’s bloodstream. This breakthrough laid the foundation for a new type of prenatal screening.
In 2008, Professor Dennis Lo and his team at The Chinese University of Hong Kong formally introduced the concept of using maternal blood cfDNA for fetal aneuploidy screening. By 2011, NIPT entered clinical use and has since rapidly expanded across the globe.
Initially designed to screen for Down syndrome (trisomy 21), NIPT technology has evolved to detect trisomy 18, trisomy 13, sex chromosome anomalies, and, more recently, rare chromosomal microdeletions and single-gene disorders (via NIPT Plus).
🧪 How Does NIPT Work?
During pregnancy, the placenta continuously sheds fetal DNA into the maternal bloodstream. NIPT isolates and analyzes this placental DNA from a simple blood draw from the mother (or gestational carrier), enabling specialists to assess chromosomal abnormalities without touching the fetus.
⏱️ When Are Results Available?
Typically, results are available within 7 to 14 days after the blood draw.
✅ Advantages of NIPT
- High Safety NIPT is completely non-invasive. It only requires a standard blood draw, eliminating the risk of miscarriage associated with procedures like amniocentesis or chorionic villus sampling (CVS).
- High Accuracy NIPT is extremely sensitive, especially for trisomy 21. Studies have shown detection rates above 99% with very low false-positive rates. While NIPT is still a screening—not diagnostic—test, its accuracy makes it a first-line option for many.
- Early Testing NIPT can be performed as early as 10 weeks into pregnancy, allowing early peace of mind and more time for planning if follow-up testing is needed.
🔍 What Does NIPT Plus Screen For?
NIPT Plus expands upon standard NIPT by screening for:
- Sex chromosome abnormalities (e.g., Turner syndrome [45,X], Klinefelter syndrome [47,XXY], Triple X [47,XXX])
- Rare autosomal trisomies (e.g., trisomy 16, trisomy 9)
- Microdeletions & microduplications, including:
- Select single-gene disorders, such as Noonan syndrome or cystic fibrosis, depending on the provider
Note: The availability and scope of NIPT Plus vary by lab and insurance coverage.
⚠️ Limitations of NIPT
Despite its many benefits, NIPT has limitations:
- Not diagnostic: A “high-risk” NIPT result should always be confirmed with diagnostic testing like amniocentesis.
- Limited for structural defects: NIPT does not screen for all types of genetic or structural abnormalities, such as congenital heart defects, which are assessed during an ultrasound scan.
- False negatives/positives: Though rare, inaccuracies can occur due to low fetal fraction, placental mosaicism (a difference between the placenta’s and fetus’s DNA), or maternal conditions like cancer or certain chromosomal abnormalities.
👩🍼 Who Should Consider NIPT?
Although initially recommended for women over 35 or those with high-risk pregnancies, current guidelines from organizations like the American College of Obstetricians and Gynecologists (ACOG) suggest that NIPT can be offered to all pregnant individuals, regardless of age or risk factors.
For intended parents using a gestational surrogate, NIPT is not automatically ordered by every OB-GYN. We recommend that intended parents speak with their surrogate and ask her to request a NIPT order from her doctor. If you’re going to test, it’s worth opting for NIPT Plus to maximize information from a single blood draw.
🧬 Is NIPT Still Necessary After Transferring a PGT-A Normal Embryo?
Even if the embryo has undergone Preimplantation Genetic Testing for Aneuploidy (PGT-A) and was labeled chromosomally normal, NIPT remains valuable.
We once encountered a tragic case where a surrogate received a PGT-A normal embryo, but the pregnancy later revealed a complex congenital heart defect. Amniocentesis confirmed trisomy 18. Had NIPT been performed, the abnormality might have been detected earlier—before the second-trimester anatomy scan.
This kind of discrepancy can occur due to a biological phenomenon called “mosaicism,” where the placenta (tested by PGT-A and NIPT) and the fetus have different genetic makeups, or due to rare technical limitations of PGT-A.
No screening test is perfect. Performing NIPT, even after PGT-A, adds an extra layer of reassurance without risk.
❓ Frequently Asked Questions (FAQ)
1. What does NIPT screen for?
NIPT screens for common chromosomal abnormalities such as trisomy 21 (Down syndrome), trisomy 18, trisomy 13, and sex chromosome disorders. NIPT Plus can detect additional microdeletions and rare genetic conditions.
2. When can I take the NIPT test?
You can take NIPT as early as 10 weeks into pregnancy. Results are usually available within 7 to 14 days. If you’re not sure how far along you are, use our Due Date Calculator to estimate your pregnancy week and see when you’ll be eligible for NIPT testing.
3. Is NIPT safe for the baby?
Yes, NIPT is completely non-invasive. It only requires a maternal blood sample and poses no risk to the fetus.
4. How accurate is NIPT?
NIPT has over 99% accuracy in detecting trisomy 21. However, confirmatory diagnostic testing is recommended for high-risk results.
5. Is NIPT necessary if my embryo was PGT-A tested?
While PGT-A screens for aneuploidy at the embryonic stage, NIPT adds an extra layer of screening during pregnancy. No test is perfect, and both together increase reassurance.
6. Does insurance cover NIPT?
Many U.S. insurance plans cover NIPT for high-risk pregnancies or for women over 35. Coverage varies by plan and provider.
7. Do surrogates automatically get NIPT ordered by their OB?
Not always. Intended parents should ask their surrogate to request an NIPT order if they want it included in care.
8. What is the difference between NIPT and NIPT Plus?
NIPT Plus screens for more genetic abnormalities, including microdeletions and single-gene disorders, beyond the standard trisomy tests.
🧾 Final Thoughts
NIPT represents one of the most impactful advancements in prenatal care. It’s available from 10 weeks, requires only a blood sample, and offers highly accurate screening for several genetic conditions—with zero risk to the fetus.
While NIPT is not mandatory in the U.S., it is widely accessible and often covered by insurance, especially for high-risk pregnancies or patients over 35. If you’re working with a surrogate, we encourage open communication and proactive requests for NIPT—and preferably NIPT Plus.
👉 Remember: No single test can guarantee a perfect pregnancy outcome. But when it comes to prenatal screening, more information—especially when risk-free—is almost always better.
📚 References and Recent Studies
- ACOG Practice Bulletin No. 226: Screening for Fetal Chromosomal Abnormalities. (2020). Obstetrics & Gynecology, 136(4), e49-e67.
- Bianchi, D. W., Parker, R. L., Wentworth, J., et al. (2014). DNA sequencing versus standard prenatal aneuploidy screening. The New England Journal of Medicine, 370(9), 799-808.
- Gregg, A. R., Skotko, B. G., Benkendorf, J. L., et al. (2016). Noninvasive prenatal screening for fetal aneuploidy, 2016 update: a position statement of the American College of Medical Genetics and Genomics. Genetics in Medicine, 18(10), 1056-1065.
- Hui, L., & Bianchi, D. W. (2021). The clinical impact of noninvasive prenatal testing. BJOG: An International Journal of Obstetrics & Gynaecology, 128(10), 1563-1568.
Medically reviewed by Dr. Diana LeBlanc, MD – Reproductive Endocrinologist at Hanabusa IVF
