What is the difference between NIPT and carrier screening?

NIPT screens for chromosomal abnormalities (e.g., Down syndrome) using fetal DNA in maternal blood. Carrier screening tests parents for gene mutations that could be passed to the child, such as cystic fibrosis or fragile X syndrome.

When should I have antenatal screening?

NIPT and first-trimester screening are typically done from 10 to 14 weeks. Carrier screening can be done before or early in pregnancy. The quad screen is performed between 15 and 22 weeks. Your provider can recommend a timeline based on your health history.

Are antenatal screening tests safe?

Yes, all screening tests described (NIPT, carrier screening, first-trimester screening, quad screen) are non-invasive and pose no risk to the pregnancy. Only diagnostic tests like CVS and amniocentesis carry a small risk of miscarriage.

Can I order a prenatal screening panel online?

Yes, at prenatalscreenings.com you can order a comprehensive prenatal screening panel online. The process is simple, and results are delivered quickly to help you make informed decisions.

What Are Antenatal Screening Tests?

Learn what antenatal screening tests are, including NIPT, carrier screening & quad screen. A 2026 US guide to prenatal test types and how to order a panel.

Antenatal screening tests are medical assessments performed during pregnancy to evaluate the likelihood that a baby has certain genetic conditions, chromosomal abnormalities, or structural defects. Unlike diagnostic tests, screening tests do not provide a definitive diagnosis but instead identify pregnancies that may be at higher risk, allowing parents and healthcare providers to make informed decisions about further testing or care. In 2026, US expectant parents have access to a range of screening options, from non-invasive prenatal testing (NIPT) to carrier screening and first-trimester screening.

Types of Antenatal Screening Tests

Non-Invasive Prenatal Testing (NIPT) – Cell-Free DNA Screening

NIPT, also known as non-invasive prenatal testing or cell-free DNA screening, analyzes small fragments of fetal DNA circulating in the mother’s blood. This test is highly accurate for detecting common chromosomal conditions such as trisomy 21 (Down syndrome), trisomy 18, and trisomy 13. NIPT can also reveal the fetal sex and, in some panels, screen for certain microdeletions. It is typically offered from 10 weeks of pregnancy onward. The test requires only a maternal blood draw and poses no risk of miscarriage, making it a popular first-line screening choice in the United States. A key metric in NIPT is the fetal fraction—the proportion of cell-free DNA from the placenta—which must be above a certain threshold for reliable results.

Carrier Screening

Carrier screening is a blood or saliva test that identifies whether a parent carries a gene mutation for an inherited disorder, such as cystic fibrosis, spinal muscular atrophy, or fragile X syndrome. Even if both parents are healthy, they may be carriers and could pass the condition to their child. In the US, carrier screening is often recommended before or early in pregnancy, and expanded panels can test for dozens of conditions. Results are reported as “screen positive” or “screen negative,” and a genetic counselor can help interpret the findings and discuss reproductive options.

First-Trimester Screening (Combined Screening)

This screening, performed between 11 and 14 weeks of pregnancy, combines a maternal blood test with a nuchal translucency ultrasound. The blood test measures two substances (PAPP-A and free beta-hCG), while the ultrasound measures fluid at the back of the fetal neck. These results are combined with maternal age to estimate the risk of Down syndrome and trisomy 18. First-trimester screening has a detection rate of about 85 percent for Down syndrome, with a false-positive rate of 5 percent.

Quad Screen (Second-Trimester Screening)

The quad screen is a blood test performed between 15 and 22 weeks of pregnancy. It measures four markers: alpha-fetoprotein, hCG, estriol, and inhibin A. This test screens for neural tube defects (such as spina bifida), Down syndrome, and trisomy 18. It is often used when first-trimester screening was not performed, or as part of integrated screening.

Integrated Screening

Integrated screening combines results from first-trimester screening (blood test and ultrasound) with the quad screen to provide a single, more accurate risk estimate. This approach can detect up to 96 percent of Down syndrome cases with a lower false-positive rate. However, it requires two blood draws and an ultrasound, and final results are not available until the second trimester.

Diagnostic Tests vs. Screening Tests

It is important to understand that screening tests are not diagnostic. If a screening test indicates an increased risk, diagnostic tests such as chorionic villus sampling (CVS) or amniocentesis can confirm or rule out a condition. CVS is performed between 10 and 13 weeks and samples placental tissue, while amniocentesis is done after 15 weeks and samples amniotic fluid. Both carry a small risk of miscarriage (approximately 1 in 300 to 1 in 500 for amniocentesis, and slightly higher for CVS). A genetic counselor can help you weigh the benefits and risks.

Key Differences at a Glance

Test Type	Timing	What It Screens For	Invasiveness
NIPT (cell-free DNA)	From 10 weeks	Trisomies 21, 18, 13; sex chromosomes; some microdeletions	Non-invasive (blood draw)
Carrier Screening	Before or early pregnancy	Inherited genetic disorders (e.g., CF, SMA, fragile X)	Non-invasive (blood/saliva)
First-Trimester Screening	11–14 weeks	Down syndrome, trisomy 18	Blood draw + ultrasound
Quad Screen	15–22 weeks	Neural tube defects, Down syndrome, trisomy 18	Non-invasive (blood draw)
Integrated Screening	First + second trimester	Same as first-trimester + quad	Blood draws + ultrasound
CVS / Amniocentesis	10–13 weeks / 15+ weeks	Diagnostic confirmation of chromosomal or genetic disorders	Invasive (needle aspiration)

How to Choose the Right Screening for You

Your choice of antenatal screening depends on your medical history, family background, and personal preferences. Many US providers now offer a prenatal paternity test alongside screening, though this is separate from medical screening. A genetic counselor can help you understand the benefits and limitations of each test, including the possibility of false positives or inconclusive results (e.g., low fetal fraction on NIPT).

NIPT: Best for high accuracy on common trisomies; no risk to pregnancy.
Carrier Screening: Essential for couples planning a family or early in pregnancy; can reveal risks for recessive disorders.
First-Trimester Screening: Provides early risk assessment with ultrasound; widely available.
Quad Screen: Useful if you missed first-trimester screening; also screens for neural tube defects.
Integrated Screening: Most accurate among non-invasive options, but requires two visits.

Remember, all screening results are risk estimates, not diagnoses. If your results show increased risk, your provider will likely recommend a diagnostic test and a meeting with a genetic counselor.

If you are ready to take the next step, you can order a prenatal screening panel online and receive your results quickly, giving you peace of mind during your pregnancy journey.