Exceptional Accuracy

Exceptional Accuracy

Harmony delivers exceptional accuracy for trisomy 21 screening in any age or risk


†Both under 35 and over 35 age groups, studies have included women ages 18-48


Extensive blinded, published validation data

The Harmony Prenatal Test is broadly studied, including 11 blinded published validation trials.1-11

In blinded prospective published trials including over 22,000 pregnant women from ages 18 to 50, Harmony demonstrated exceptional sensitivity and specificity. 1-2,4,7,11

Combined Harmony Performance Across All Clinical Studies

Trisomy 21 Performance1-7, 11-13
Detection Rate > 99%
False-Positive Rate < 0.1%
Trisomy 18 Performance1-7, 11-13
Detection Rate  97.4%
False-Positive Rate < 0.1%
Trisomy 13 Performance1-7, 11-13
Detection Rate  93.8%
False-Positive Rate <0.1%


Harmony is Validated for Pregnant Women of Any Age or Risk Categories† and Trusted by Clinicians Worldwide

  • Studied extensively in blinded prospective published trials including >22,000 pregnant women. 1-2,4,7,11

  • Clinicians in more than 100 countries have trusted Harmony to screen more than 500,000 pregnancies.12

†Harmony has been studied extensively in women both under and over age 35, studies have included women ages 18-48.

The Harmony Prenatal Test Shows Clear Difference Between High-Risk and Low-Risk Results12

The below graphs represent data from the blinded prospective head to head comparison study of First Trimester Screening (FTS*) against Harmony. 11-12

Data represent 15,841 patients in a general pregnancy population.12

Harmony provides clear results for trisomy 21 risk, generating a wide separation between high-risk and low-risk values, with only extremely rare (less than 1 in 1000) false-positive results.12

*Serum PAPP-A, total or free ß-hCG & Nuchal Translucency

Exceptional positive predictive value (PPV)

Positive Predictive Value (PPV) is the likelihood that a positive test result is a true-positive. PPV varies by population.

Harmony’s extremely low false-positive rate of less than 0.1% gives it a high PPV for trisomy 21.1,11 Harmony has a PPV for trisomy 21 of 93% in pregnancies in women age 35, where the incidence of fetal trisomy 21  is 1 in 249.1 In contrast, for this same population, the PPV of traditional first trimester screening is 6%.15

Positive predictive value (PPV) and incidence

PPV depends on the incidence of the condition being tested. The rarer the condition, the higher the probability a positive result is a "false positive". 16

Testing for extremely rare conditions (1 in 10,000 incidence rate) in a routine genetic test may:

  • Increase the cumulative false-positive rate of the entire test
  • Substantially lower the overall PPV of the test
1. Norton et al. Am J Obstet Gynecol. 2012 Aug;207(2):137.e1-8. 
2. Nicolaides et al. Am J Obstet Gynecol. 2012 Nov;207(5):374.e1-6. 
3. Ashoor et al. Ultrasound Obstet Gynecol. 2013 Jan;41(1):21-5. 
4. Verweij et al. Prenat Diagn. 2013 Oct;33(10):996-1001. 
5. Ashoor et al. Am J Obstet Gynecol. 2012 Apr;206(4):322.e1-5. 
6. Sparks et al. Am J Obstet Gynecol. 2012 Apr;206(4):319.e1-9. 
7. Gil et al. Fetal Diagn Ther. 2014;35:204-11. 
8. Nicolaides et al. Fetal Diagn Ther. 2014;35(1):1-6. 
9. Hooks et al. Prenat Diagn. 2014 May;34(5):496-9. 
10. Sparks et al. Prenat Diagn. 2012 Jan;32(1):3-9. 
11. Norton M, et al, N Engl J Med. 2015 Apr 23;372(17):1589-97.
12. Data on file
13. Juneau et al. Fetal Diagn Ther. 2014;36(4):282-6.
14. Estimate based on an average-risk population with prevalence for T21, T18, and T13 of 1 in 700, 1 in 5000, and 1 in 16000 respectively.
15. ACOG Practice Bulletin No. 77. Obstet Gynecol 2007;109:217-27.
16. http://phprimer.afmc.ca/Part2-MethodsStudyingHealth/Chapter6MethodsMeasuringHealth/Interpretingtestsonindividuals
17. Ultrasound Obstet Gynecol 1999;13:167-170. 2. Shaffer LG, Lupski JR. Molecular mechanisms for constitutional chromosomal rearrangements in humans. Annu Rev Genet. 2000;34:297-329. [PMID: 11092830]