Prenatal Screening Tests                                                                                                              

(examples: NIPT (non-invasive prenatal testing), such as the Harmony test, ultrasound, first trimester screening)                

  • Evaluate the chance for certain conditions in a pregnancy
  • Pose no risk to the pregnancy    
  • Are followed by additional testing if a diagnosis is desired
  • Performed as early as 10 weeks of pregnancy
  • May indicate an increased chance for a condition in an unaffected pregnancy (“false positive”) or a low chance for a condition in an affected pregnancy (“false negative”)

Prenatal Diagnostics Tests 

(examples: amniocentesis, CVS (Chorionic Villus Sampling))

  • Can diagnose and/or rule out certain conditions in pregnancy
  • More definitive and comprehensive than prenatal screening tests
  • Invasive and pose a risk of pregnancy loss
  • Performed at 10-13 weeks (CVS) or 15-20 weeks (amniocentesis) of gestation
  • Cannot detect or rule out all genetic or chromosomal conditions

What prenatal screening options are available in the first trimester?

What prenatal diagnostic tests are available?


Using a DNA-based technology, the Harmony Prenatal Test has been shown to identify more than 99% of pregnancies with Down syndrome.1 By comparison, traditional blood tests can miss as many as 15% of pregnancies with Down syndrome.2

The Harmony Prenatal test is also much less likely than traditional tests to give you a false-positive result, meaning there is much less chance your doctor would recommend follow-up invasive testing like amniocentesis.

The Harmony Prenatal Test is a screening test. Results should be confirmed with diagnostic testing such as amniocentesis and chorionic villus sampling  (CVS). 

Read more about the accuracy of the Harmony Prenatal Test.


1.        Stokowski et al. Prenat Diagn. 2015 Dec;35(12):1243-6.

2.       ACOG Practice Bulletin 163 Obstet Gynecol. 2007 Jan;109(1):217-27.



When you are pregnant, your blood contains pieces of DNA from your developing baby. The Harmony Prenatal Test is a test that analyzes DNA in a sample of your blood to assess the chance of Down syndrome (trisomy 21) and other chromosome conditions called trisomy 18 and trisomy 13.


The Harmony Prenatal test delivers clear answers as early as the first trimester with a single blood draw. Other screening tests for Down syndrome are performed later in pregnancy and require multiple office visits. Traditional 1st trimester serum screening tests are associated with a false-positive rate as high as 5%.
The Harmony prenatal test uses a unique method of targeted DNA analysis that, combined with extensive quality controls, achieves over 99% detection rate and a false-positive rate less than 0.1%.1


1.         Stokowski et al. Prenat Diagn. 2015 Dec;35(12):1243-6.

2.        ACOG Practice Bulletin 163 Obstet Gynecol. 2007  Jan;109(1):217-27.


Yes, the Harmony Prenatal Test now has the option for Sex chromosome Aneuploidy (monosomy X, XXX, XXY, XYY and XXYY) and for the microdeletion syndrome called 22q11.2.


Yes. Recent professional society guidelines support the offering of non-invasive prenatal testing to the general population. 1-2 The Harmony Prenatal Test has been extensively validated in women both over and under 35. 3 Most babies with Down syndrome are born to women who are less than 35 years old, even though the risk of Down syndrome in a pregnancy increases with a woman’s age. 4


  1. Benn et al. Prenat Diagn. 2015 Aug;35(8):725-34.
  2. Gregg et al. Genet Med. 2016 Oct;18(10):1056-65.
  3. Norton et al. New England J of Medicine. 2015; 372(17):1589-1597.
  4. California Prenatal Screening Program 2009

As early as 10 weeks into your pregnancy, you can take the Harmony Prenatal Test with a simple blood draw. 


In seven days or less, your healthcare provider will receive the results and can share them with you.


You can find more information on trisomy 21, trisomy 18 and trisomy 13 in What We Test For section



Yes. Harmony can be used in twin pregnancies for Trisomies 21, 18 and 13. sex chromosome aneuploidy and microdeletion syndrome 22q11.2 can not be tested for twin pregnancies.


Yes. In most cases, the Harmony Prenatal Test can be used in pregnancies conceived through in vitro fertilization (IVF).


For questions that relate to your specific case and personal concerns, it’s best to talk to your healthcare provider. Here is a list of questions for your healthcare provider you can print for your next visit.


Contact our client services team

Tel: 925.854.6246

*Information provided in this section is not comprehensive. All information should be reviewed with a health-care provider. All options stated here may not be available to all women in all regions.

1.        ACOG Committee on Practice Bulletin No. 163. Obstet Gynecol. 2016 May;127(5):e123-37

The Harmony Prenatal Test is a non-invasive prenatal test (NIPT) based on cell-free DNA analysis and is considered a prenatal screening test, not a diagnostic test. Harmony does not screen for potential chromosomal or genetic conditions other than those expressly identified here. All women should discuss their results with their healthcare provider, who can recommend confirmatory, diagnostic testing where appropriate. The Harmony Prenatal Test was developed, and its performance characteristics determined by Ariosa Diagnostics, Inc., a CLIA-certified and CAP-accredited clinical laboratory in San Jose, CA USA. This testing service has not been cleared or approved by the US FDA.

HARMONY is a trademark of Roche. All other product names and trademarks are the property of their respective owners.


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