Harmony PreNatal Test
Non-Invasive Prenatal Test (NIPT)
Harmony Pre-Natal Test Information For Patients
Non-invasive prenatal testing (NIPT) analyses cell-free DNA circulating in the pregnant mother’s blood. It is a new option in prenatal screening for Down syndrome (Trisomy 21) and other fetal chromosomal conditions (Trisomies 18 and 13), X and Y chromosome conditions. This test can be requested for any singleton pregnancy, including in vitro fertilization (IVF) pregnancies with egg donors. It can also be requested for twin pregnancies conceived naturally or by IVF using the patient’s own egg.
Below is a detailed explanation of the Harmony Pre-Natal Test, and below this you can find the transcript of this video.
About the Ariosa Harmony™ Prenatal Test
DNA from the fetus circulates in the mother’s blood. Cell free DNA (cfDNA) results from the natural breakdown of fetal cells (presumed to be mostly placental) and clears from the maternal system within hours of giving birth.
During a pregnancy, cfDNA can be tested to give the most accurate screening approach in estimating the risk of fetus having a common chromosome condition sometimes called a trisomy. This occurs when there are three copies of a particular chromosome instead of the expected two. The test looks to detect the following trisomies:
Trisomy 21 is the most common trisomy, at the time of birth. Also called Down syndrome, it is ssociated with moderate to severe intellectual disabilities and may also lead to digestive disease, congenital heart defects and other malformations.
Trisomy 18 (Edwards syndrome) and Trisomy 13 (Patau syndrome) are associated with a high rate of miscarriage. These babies are born with severe brain abnormalities and often have congenital heart defects as well as other birth defects. Most affected individuals die before or soon after birth, and very few survive beyond the first year of life.
Sex chromosome conditions. The sex chromosomes (X and Y) determine whether we are male or female. X and Y chromosome conditions occur when there is a missing, extra, or incomplete copy of one of the sex chromosomes. The Harmony with X, Y test can assess risk for XXX, XYY, XXYY, XXY (Klinefelter Syndrome), and a missing X chromosome in a girl (Turner Syndrome). There is significant variability in the severity of these conditions, but most individuals have mild, if any, physical or behavioural features. If the mother is interested in having this optional testing, she should talk with her healthcare provider to determine if it is right for her.
The testing is non-invasive: it involves taking a blood sample from the mother. The pregnancy is not put at risk of miscarriage, or from other adverse outcomes that are associated with invasive testing procedures such as amnioecentesis.
Clinical studies have shown that the Ariosa Harmony™ Prenatal Test has exceptional accuracy for assessing fetal trisomy risk.
A “high risk” result is indicative of a high risk for a trisomy. The test identifies in singleton pregnancies more than 99% of fetuses with trisomy 21, 98% of fetuses with trisomy 18, and 80% of fetuses with Turner Syndrome . X and Y analysis provides >99% accuracy for fetal sex. Accuracy detecting other sex chromosome anomalies varies by condition
After the test, the number of women required to have a CVs or amniocentesis is less than 1%.
It is important to note that if the test results show there is a high risk that the fetus has trisomy 21, 18, 13 or sex chromosome conditions, it does not mean that the fetus definitely has one of these conditions, although it is highly likely. For this reason, in the event of a “high risk” (or positive) result, follow-up testing by an invasive procedure is recommended.
In the same way if the test results show that there is a “low risk” that the fetus has trisomy 21, 18, 13 or sex chromosome conditions, it is unlikely that the fetus has one of these conditions. However, there is a very small risk that not all trisomy fetuses will be detected.
Who can have the test?
Ariosa Harmony™ Prenatal Test can be ordered for women with pregnancies of at least 10 weeks’ gestational age. The Harmony™ Prenatal Test can now be ordered for all IVF Singleton pregnancies, including those with egg donors. Samples from pregnant women with twins naturally conceived, or those conceived using the patient’s own egg, are also accepted. This test does not assess risk for mosaicism, partial trisomies or translocations.
The results will be ready in approximately two weeks. On the basis of the NIPT result and the ultrasound findings, a patient can decide whether or not she wants to have an invasive procedure such as amniocentesis or CVS.
There needs to be enough fetal DNa in the maternal blood sample to be able to provide a result. If there is insufficient fetal DNA in the sample (occurring in 3% of cases), another blood sample from the mother may be required. This will be processed in the laboratory at no extra charge .
What is the process?
Once the mother has taken an independent personal decision that she wants to have the NIPT performed, she will be asked to sign a consent form and her blood sample can be taken from a vein in her arm
Who carries out the analysis of the test?
The sample and completed request form are sent to TDL Genetics, after which they will be referred to Ariosa Diagnostics Inc, USA. Ariosa performs the Harmony™ Prenatal Test on the DNA extracted from her blood sample.
Will the mother need to have any other test?
The Ariosa Harmony™ Prenatal Test does not provide information on other rare chromosomal abnormalities. If the ultrasound scan shows a high nuchal translucency or other major physical defects such as brain abnormalities, the risk for some rare chromosomal defects may be high. In such cases, the mother may choose to have a CVS or amniocentesis.
The non-invasive prenatal test does not provide information on other physical defects such as spina bifida, or information on fetal growth. It is therefore advisable that the mother has all the usual ultrasound scans during her pregnancy.
Video title: Harmony Prenatal Test
The Harmony, non-invasive, prenatal test is the latest, most advanced test available for screening for chromosome abnormalities such as Down’s syndrome or Edward’s syndrome or Patau’s syndrome. It is a blood test and it takes up to two weeks for the result. Because it’s a blood test, there’s no risk either to you or the baby and it holds a very high diagnostic accuracy.
The result comes in two forms. It will be high risk or low risk and it has between 95% and 99% accuracy. If the result is low risk, that’s very, very unlikely that the baby has Down’s syndrome, though there is a very small chance that it does. If the result is high risk, many people might choose to go on and have a diagnostic test such as an amniocentesis or a chorionic villus sampling.