NIPT vs. sequential screening: Which test detects more?

Accurate information about your baby's health during pregnancy is important for identifying and managing potential health risks.

This article provides a clear, evidence-based comparison of NIPT vs. sequential screening, two of the most commonly used prenatal screening options. While both evaluate the risk of genetic conditions, they differ in important ways.

We’ll explain everything you need to know about both so you can make the best choice for you and your future baby.

What is noninvasive prenatal testing (NIPT)?

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Non-invasive prenatal testing (NIPT) is a screening method used during pregnancy to assess the risk of certain genetic abnormalities in the fetus. It involves analyzing small fragments of cell-free DNA (cfDNA) found in the mother's bloodstream, the proportion of which is called the fetal fraction.

NIPT is typically performed as early as 9–10 weeks of gestation and requires only a blood sample from the mother’s arm, making it completely non-invasive and safe for both mother and baby.

The test is most commonly used to screen for chromosomal conditions, sex chromosome abnormalities, and fetal sex (if requested).

It’s important to note that NIPT is a screening test, not a diagnostic one. It estimates the likelihood of the fetus having a certain genetic condition but doesn’t confirm a diagnosis. If results indicate a high risk, your healthcare provider may recommend diagnostic follow-up tests such as amniocentesis or chorionic villus sampling (CVS) for confirmation.

What is the sequential screening test?

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Sequential screening is a two-part prenatal screening test that helps evaluate the risk of certain chromosomal disorders and neural tube defects in a developing fetus. The test combines:

1. A blood test and an ultrasound in the first trimester

2. A follow-up blood test in the second trimester 

The table below outlines the schedule, markers measured, and what abnormal results may indicate:

NIPT vs. sequential screening: Key areas to compare

To help you better understand the value of these two tests and the differences in the information they provide, we’ll compare them across the following aspects:

1. Conditions screened

2. Results accuracy

3. Timing and turnaround

4. Cost, availability, and accessibility

Below, we’ll unpack how each test performs in these areas.

1. Conditions screened

One of the most important differences between NIPT and sequential screening is the scope of conditions each test can detect.

NIPT covers a comprehensive range of chromosomal abnormalities, as most panels screen for the three most common trisomies:

1. Down syndrome (Trisomy 21)

2. Edwards syndrome (Trisomy 18)

3. Patau syndrome (Trisomy 13)

In addition, many NIPT panels also include:

• Sex chromosome conditions, such as Turner syndrome and Klinefelter syndrome

• Select microdeletion syndromes

• Fetal sex determination

Because of its high sensitivity and early timing, NIPT is the best genetic testing option for couples who want a comprehensive chromosomal analysis as early as possible during pregnancy. 

In contrast, sequential screening focuses on a narrower range of genetic conditions but also includes the fetus’ risk for neural tube defects. It screens for:

• Trisomy 21 and trisomy 18

• Neural tube defects (such as spina bifida)

• Other potential structural issues, identified via nuchal translucency

While sequential screening doesn’t cover as many chromosomal conditions as NIPT, it’s one of the only noninvasive methods that includes neural tube defect screening. If you want broad genetic insights, go with NIPT, but choose sequential screening if you’re more worried about structural risks like spina bifida.

Here’s how one Reddit user described their experience:

[Reddit](https://www.reddit.com/r/BabyBumps/comments/f2jmvc/comment/fhfmx8v/)(480)

2. Results accuracy

Accuracy is one of the biggest concerns for expectant parents choosing a prenatal screening test and looking for reassurance, not more confusion. 

NIPT is widely considered the most accurate prenatal screening method for common chromosomal conditions as it:

• Detects 98–99% of pregnancies affected by trisomy 21 (Down syndrome) and trisomy 18 (Edwards syndrome)

• Has a low false-positive rate of around 0.2% for trisomy 21 and trisomy 18

• Detects 79–92% of sex chromosome abnormalities, like Turner or Klinefelter syndrome

• It has a low occurrence of inconclusive results of around 2–3%

Sequential screening combines results from blood tests and a first-trimester ultrasound, followed by a second blood test. This two-step method provides:

• 90% detection rate for trisomy 21 and trisomy 18

• 80% detection rate for open neural tube defects, like spina bifida

• Slightly lower accuracy (85–90%) when only the first blood test is used without full sequential data

While sequential screening can be less precise than NIPT for chromosomal conditions, its value lies in that it also screens for structural issues and is routinely included in standard prenatal care programs.

3. Timing and turnaround

One of the biggest advantages of NIPT is how early it can be done. You can take the test as early as 10 weeks into your pregnancy, and results are typically available within 7–10 days, depending on the lab and provider.

Sequential screening involves two steps over several weeks. The first phase happens between 11 and 13 weeks and includes a blood test and a nuchal translucency ultrasound. If the results show low risk, you'll return for a second blood test between 16 and 18 weeks. 

Once both parts are complete, your provider will calculate the final results, meaning you'll typically receive a full report between 18 and 20 weeks of pregnancy.

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4. Cost, availability, and accessibility

NIPT is widely available through many obstetrics and maternal-fetal medicine clinics across the U.S. Thanks to its high accuracy and non-invasive nature, it has become a go-to option for many expecting parents. 

However, NIPT tends to be more expensive than other screening methods, and the costs can vary depending on your specific situation: 

• Typical range: $100 to over $1,000

• Insurance coverage: Often only covered if you meet certain criteria, such as being 35 or older, having a high-risk pregnancy, or a personal/family history of chromosomal conditions

• Out-of-pocket costs: Can be significant if you don’t meet insurance requirements, especially with more advanced panels

Many testing companies offer payment plans or cost estimators, so check with your provider and the lab to understand what you’ll actually pay.

Sequential screening is typically less costly and more likely to be fully covered by insurance, especially as it has been used longer and is considered a standard screening test in many practices.

It's also broadly available at most OB/GYN clinics and prenatal care centers and doesn't require specialized labs or handling like NIPT.

The actual costs vary widely depending on the company you use, from $100 to several hundred dollars. 

[Reddit](https://www.reddit.com/r/BabyBumps/comments/6hrntf/comment/dj0whap/)(340)

NIPT vs. sequential screening: Which test should you choose?

Both NIPT and sequential screening offer safe, noninvasive ways to learn more about your baby’s health, but they serve slightly different purposes.

NIPT is more accurate for detecting common chromosomal abnormalities and can be performed earlier in pregnancy. However, its higher cost and limited insurance coverage may be barriers.

Sequential screening offers a broader view of fetal development, including the chance to detect neural tube defects, which NIPT typically doesn’t cover. It’s often more accessible and fully covered by insurance, making it a practical and valuable option for many families. 

While both methods are valuable in prenatal care, they don’t tell the full story of your family's genetic health. If you’re looking for a more comprehensive picture — not just of your baby’s current risks, but also of genetic conditions you and your partner might pass on —  carrier screening through whole-genome sequencing (WGS) can offer that clarity.

Nucleus provides this expanded preconception genetic screening service to identify carrier risks for hundreds of inherited conditions, giving you additional insights.

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Nucleus: A smarter start to family planning

Nucleus is a cutting-edge DNA analysis platform that supports informed family planning through whole-genome sequencing. With clinical-grade precision and a 99.9% accuracy, Nucleus offers future parents a powerful window into their genetic makeup, far beyond what standard carrier screenings provide.

With comfortable, at-home cheek swabs, Nucleus can help you:

• Identify carrier status for hundreds of inherited conditions, including rare and serious genetic disorders

• Understand your risk for over 900 diseases, such as cardiovascular, neurological, and certain types of cancer

• Learn about genetic traits that can influence your future children, like height, cognitive ability, and more

Nucleus also considers how lifestyle and environmental factors might impact your gene expression and overall health, making the results more meaningful and actionable. It further enhances this analysis with AI-driven insights, helping you make sense of complex genetic data with greater clarity and context.

Your comprehensive reports are delivered digitally and written in clear, accessible language with easy-to-interpret visuals. If you need expert support, Nucleus can connect you with licensed genetic counselors through its partnership with SteadyMD.

How to get started with Nucleus

The Nucleus test kit costs $499 or $798 for couples’ testing, saving you $200. The test is also eligible for HSA/FSA coverage, so you can pay less out of pocket. The cost includes your test, return shipping, and unlimited access to your current and future reports.

Getting started is simple:

1. Sign up for Nucleus

2. Provide your personal information

3. Order the test

After submitting your sample, you’ll receive your results within 6–8 weeks. As Nucleus expands its database, you’ll receive ongoing updates and new reports to keep your genetic insights current and relevant.

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Check out our other resources on prenatal genetic testing:

Featured image source: Edward Jenner