Why Offer Harmony?

Doctor talking to expecting parents

Why offer the Harmony test as a first-line screen?

Exceptional performance

Higher detection rate and lower false positive rate for trisomy 21 compared to first trimester screening1

Exceptional performance in the general population


The Harmony test outperformed traditional first-trimester screening (FTS) in a landmark study (NEXT) published in the New England Journal of Medicine.2 In this prospective blinded study, the Harmony test was found to be superior to FTS in terms of detection rate, false positive rate and positive predictive value for trisomy 21. 

Down Syndrome
Performance of the Harmony test

The Harmony test delivers consistent, industry-leading performance for trisomy 21, trisomy 18 and trisomy 13 across clinical studies.3

22q11.2 microdeletion

22q11.2 microdeletion, an absence of a small piece of chromosome 22,4 happens in about 1 in 1000 pregnancies.5,6 It is the second most common genetic cause of heart defects and developmental delay after Down syndrome,7 and is the underlying cause of DiGeorge and velocardiofacial syndromes (VCFS). 22q11.2 microdeletion is not reliably detected by routine prenatal screening or karyotype.7

Unlike trisomies, maternal age is not a risk factor for the microdeletion5 and family history cannot reliably predict its occurrence, as more than 90% of affected individuals have no family history.8

The performance of the Harmony test for 22q11.2 microdeletion has been evaluated in a study including over 1900 samples, including 129 with confirmed deletions. The Harmony test was able to reliably identify pregnancies at risk for 22q11.2 deletions of 3Mb and smaller with a low false positive rate.5

This test has also been used in a prospective clinical evaluation where detection of both common and smaller, nested 22q11.2 deletions was demonstrated with a low false positive rate. Incorporating this screening test into clinical care can enhance detection of pregnancies at risk for 22q11.2 deletion syndrome while avoiding unnecessary invasive procedures and maternal anxiety associated with false positive results.9

Sex chromosome aneuploidies

Sex chromosome aneuploidies

Individuals typically have two X chromosomes or one X and one Y chromosome. Any variation from the typical number of X and Y chromosomes in the cells is called a sex chromosome aneuploidy (SCA). SCAs have a combined prevalence of about 1:500.10 Conditions associated with SCAs have widely variable clinical features that are often subtle but can include birth defects, infertility and learning differences. Most CAs are not reliably detected by routine prenatal screening.

Twin pregnancies

Performance of the Harmony test has been published in peer-reviewed studies including over 1,300 twin pregnancies, and Harmony has been used in NIPT studies around the world.11,12,13,14,15,16


Clinical scenarios included in published Harmony twin studies

  • Monochorionic twins
  • Dichorionic twins
  • Twins conceived with in vitro fertilization (IVF)
  • Twins conceived naturally
  • Pregnancies where both twins have aneuploidy
  • Pregnancies where only one twin has aneuploidy
  • First trimester testing
  • Second trimester testing


Many professional societies such as the American College of OB/GYN, The International Society for Prenatal Diagnosis (ISPD) and American College of Medical Genetics and Genomics (ACMG) support offering NIPT as a first-line screen.17-19

"The following protocol options are currently considered appropriate: cfDNA screening as a primary test offered to all pregnant women."18

"ACMG recommends informing all pregnant women that NIPS is the most sensitive screening option for trisomy 21, trisomy 18, and trisomy 13."19

  1. Norton et al. New Engl J of Med. 2015; 372(17):1589-1597.
  2. Norton et al. Am J Obstet Gynecol.2012 Aug;207(2):137-8.
  3. Stokowski et al. Prenat Diagn. 2015 Dec;35(12):1243-6.
  4. Schmid et al. Fetal Diagn Ther 2017; Doi:10.1159/000484317.
  5. Bevilacqua, E et al.  Intl Society of Ultrasound in Obstet and Gynecol. 58,4 (2021): 597-602. doi:10.1002/uog.23699
  6. Wapner et al. N Engl J Med 012;367:2175-2184.
  7. McDonald-McGinn et al. Gnet Med.2001 Jan-Feb:3(1):23-9.
  8. Bassett et al. JPediatr. 2011 Aug;159(2):332-9.
  9. Bevilacqua, E et al.  Intl Society of Ultrasound in Obstet and Gynecol. 58,4 (2021): 597-602. doi:10.1002/uog.23699
  10. Thompson and Thompson. Genetics in Medicine, Sixth Edition. Robert L Nussbaum, Roderick Mclnnes, Willard Huntington, Saunders, 2001.
  11. Gil M, et al. Ultrasound Obstet Gynecol. 2019 Jun;53(6):734-742.
  12. Struble C et al. Fetal Diagn Ther. 2013;35(3):199-203.
  13. Bevilacqua E, et al. Ultrasound Obstet Gynecol. 2015;45(1):61-66.
  14. Stokowski et al. Prenat Diagn. 2015 Dec;35(12):1243-6.
  15. Sarno L, et al. Ultrasound Obstet Gynecol. 2016;47(6):705-711.
  16. Jones KJ, et al. Obstet Gynecol. 2018 51:274-277.
  17. American College of Obstetricians and Gynecologists’ Committee on Practice Bulletins—Obstetrics et al. “Screening for Fetal Chromosomal Abnormalities: ACOG Practice Bulletin, Number 226.” Obstetrics and gynecology vol. 136,4 (2020): e48-e69. doi:10.1097/AOG.0000000000004084
  18. Benn et al. Prenat Diagn 2015; 35: 725–734.
  19. Gregg et al. Genetics in Medicine 2016 Oct; 18(10):1056-65.