Thanks to rapid advances in genetic testing many cell-free DNA prenatal screening tests are available to you in your patient today. One very important quality metric is called fetal fraction. If fetal fraction is not incorporated in the assessment of a trisomy, then potentially only the maternal portion is analyzed and without the baby, thereby leading to potential false negatives or discordant calls.

Professional societies like ACOG and ACMG have included statements and information on the importance of measuring fetal fraction in a prenatal test. Cell-free DNA prenatal screening was originally conceived and designed to reduce unnecessary invasive testing and anxiety for expecting parents.

The Harmony Prenatal Test was developed by Ariosa Diagnostics, a CLIA-certified laboratory. As with other lab-developed tests, it has not been cleared or approved by the FDA and is not available for sale as an IVD in the US. Non-invasive prenatal testing (NIPT) based on cell-free DNA analysis is not diagnostic; results should be confirmed by diagnostic testing.