Technology That Drives Results

Technology That Drives Results

The accuracy of the Harmony Prenatal Test rests on a proprietary targeted methodology and careful measurement of fetal DNA.

A proprietary DNA-based methodology

Harmony Prenatal Test relies on a proprietary targeted DNA-based technology to provide exceptionally accurate results. 

  • Cell-free DNA—short DNA fragments—of the mother and the fetus circulate in maternal blood
  • Harmony analyzes fragments from specific chromosomes, rather than all chromosomes
  • Targeted analysis results in higher throughput and accurate trisomy risk assessment


During pregnancy, cell-free DNA (cfDNA) fragments from the fetus and placenta circulate in the maternal bloodstream.


A directed approach

In contrast to tests that use MPSS (massively parallel shotgun sequencing), randomly sequencing all cell-free DNA (cfDNA), the Harmony test focuses on cfDNA from the chromosomes of interest. This unique, directed approach allows deeper analysis and ultimately yields more accurate results.

Importance of fetal fraction

The Harmony methodology incorporates extensive quality controls:

  • Single nucleotide polymorphism (SNP) analysis is used to precisely quantify cfDNA and determine the fetal DNA contribution in a sample
  • Harmony also incorporates the fetal DNA measurement into its risk assessment using FORTE, a proprietary algorithm, to more clearly distinguish high and low risk results



Fetal fraction assessment is particularly important at low fetal fractions, where other methodologies have demonstrated a larger number of discordant results.

These important controls are not included at all in some cfDNA-based trisomy tests, increasing the risk of both false-positive and false-negative results.

Harmony uses fetal fraction for more robust results. Using the same data, the graphs below compare z-score vs. FORTE