Fetal Medicine Center’s Clinical Use Shows Non-Invasive Prenatal Testing Can Improve Prenatal Care
SAN JOSE, CALIF., June 10, 2013 – The Harris Birthright Centre for Fetal Medicine today released
results from a clinical implementation study (http://onlinelibrary.wiley.com/doi/10.1002/uog.12504/full) on
the use of Ariosa Diagnostics’ Harmony™ Prenatal Test in a general screening population. The test uses
cell-free DNA (cfDNA) testing from maternal blood to assess fetal genetic conditions such as trisomy 21,
which causes Down syndrome. The test is the first of its kind to be studied for use as part of standard
prenatal care. The study looked at the feasibility, reliability and utility of performing the test in a general
screening population, not just for high-risk pregnancies, and demonstrated that cfDNA testing can be
safely incorporated into routine prenatal care to reduce unnecessary invasive testing, like amniocentesis.
Professor Kypros Nicolaides, a world-renowned maternal fetal medicine specialist and one of the authors
of the study, said, “The results of our study demonstrate the value of cfDNA testing in routine screening
for trisomies. This technology represents one of the greatest advances in prenatal medicine and can help
guide better management for any pregnant woman.”
The algorithm used in the study to evaluate all pregnant women suggests that medical clinics can safely
incorporate the Harmony test into standard prenatal care. Previously, cfDNA testing was recommended
only for use in pregnancies at higher risk for fetal trisomies, which occur when an extra third copy of a
chromosome is present.
The study of 1,005 women demonstrated that cfDNA testing has significantly lower false positive rates
compared to current screening methods. The cfDNA testing method identified all trisomies with a false
positive rate of only 0.1%, compared to 3.4% from conventional screening. Non-invasive cfDNA testing
substantially reduced the rate of referrals to unnecessary invasive testing methods, which carry an
inherent risk of miscarriage. These findings support the Harmony test as a safe and accurate first step in
screening for any pregnant women.
Benefit to Prenatal Care
The manner in which Harmony Test results are reported – either with a high or low-risk result – allow
parents to decide whether or not to undergo additional procedures depending on their level of risk. The
Harmony Test, performed as early as 10 weeks’ gestation, gives parents reassurance that the fetus is
unlikely to have certain genetic conditions. In cases where a fetus may be at high risk for trisomy,
physicians should provide parents with extra time for decision-making and preparation for future
treatment and planning.
The data for this study was derived from clinical implementation of cfDNA testing in screening for
trisomies 21, 18 and 13 during the 10th gestational week in women with singleton pregnancies attending
The Fetal Medicine Centre in London, UK, between October 2012 and April 2013. A two-stage approach
to screening was used, with two visits, one at 10 weeks and another at 12 weeks.