This non-invasive prenatal testing UK (NIPT) analyses cell-free fetal DNA circulating in the pregnant mother’s blood. It is a new option in prenatal screening for Down syndrome (trisomy 21) and other common fetal chromosome conditions such as Edwards syndrome (trisomy 18) and Patau syndrome (trisomy 13).
This test can be done in naturally conceived as well as IVF pregnancies and in both singleton and twin pregnancies.
BOOK A HARMONY TEST
About the 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 a fetus having a common chromosome condition such as Down syndrome (trisomy 21). This occurs when there are three copies of chromosome 21 instead of the normal two. The test looks to detect the following trisomies:
Down Syndrome (trisomy 21) is the most common trisomy at the time of birth. It is associated with moderate to severe intellectual disabilities and may also lead to digestive disease and congenital heart disease and other malformations.
Edwards Syndrome (trisomy 18) and Patau syndrome (trisomy 13) 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 defects. Most affected individuals die before or soon after birth and very few survive beyond the first year of life.
Fetal Sex Chromosomes
Harmony Prenatal Test can also be used to evaluate X and Y sex chromosomes as early as 10 weeks.
You have the option to test for conditions caused by having an extra or missing copy of the X or Y chromosomes, including Turner and Klinefelter syndromes (This is only available for singleton pregnancies).
Risk of the Harmony Prenatal Test:
The Harmony non-invasive prenatal testing 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 amniocentesis. So this is a non invasive prenatal test. The risk of miscarriage secondary to invasive tests such as chorionic villus sampling (CVS) and amniocentesis is very distressing particularly if the baby is chromosomally normal.
To obtain a result from the Harmony blood test, there needs to be enough fetal DNA in the maternal blood. If there is insufficient fetal DNA in the sample (occurring in 3-5% of cases), another blood sample from the mother may be required. This will be processed in the laboratory at no extra charge.
The amount of fetal DNA in the maternal blood increases as pregnancy progresses and so the risk of there being insufficient fetal DNA in the sample is greater the earlier the sample is taken.
There is also a lower level of fetal DNA in overweight women and so the risk of there being insufficient fetal DNA in the sample is also increased in these cases.
Harmony Prenatal Test Accuracy:
Clinical studies have shown that the Ariosa Harmony Prenatal Test has exceptional accuracy for detecting fetal trisomies.
A ‘High Risk’ Harmony Prenatal Test result is indicative of a high risk for a trisomy abnormality.
The test identifies more than 99% of fetuses with Down syndrome (trisomy 21), 97% of fetuses with Edwards syndrome (trisomy 18) and 80% of those with Patau syndrome (trisomy 13).
After the test, the number of women required to have a CVS or amniocentesis is less than 1%.
Conventional screening will detect approximately 70-80% of pregnancies with Down syndrome.
It is important to note that if the test result show there is a high risk that the fetus has trisomy 21, 18 or 13, 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’ result, follow-up testing by an invasive procedure is recommended before any consideration for management of the pregnancy.
In the same way if the test result shows that there is a ‘Low Risk’ that the fetus has trisomy 21, 18 or 13, it is unlikely that the fetus has one of these conditions. However, there is a very small risk that not all trisomy foetuses will be detected.
All results are interpreted by Mr Penman, Consultant Specialist in Fetal Medicine, in the context of clinical and familial data. Patients should continue with their usual scan appointments following the Harmony testing.
Who Can Have The Test?
The test is suitable for any pregnant woman who has had an ultrasound scan to confirm that their pregnancy is a singleton pregnancy, that the fetus is alive, and that the pregnancy is equivalent to a gestation of 10 weeks or more. The test does not assess the risk for mosaicism, partial trisomies or translocations. The Harmony Prenatal Test results will be ready in approximately 7-10 days.
Who Carries Out The Test?
Mr Penman will preform all the scans, complete the necessary paperwork and personally take you blood sample. The sample along with your personal information (including name, date of birth, gestational age) is sent to The Doctors Laboratory based in London where the Harmony Prenatal Test is completed.
If you would like to have more information on Harmony Prenatal Testing fees, please click here.
If you would like to book a Harmony Prenatal Test please go to the Baby Scan Booking Form
Please note that since late 2015 the samples are no longer sent to Ariosa Diagnostics Inc, based in San Jose, CA, USA. for the test to be done. With the transfer of the technology to London, the time taken for patients to receive their result has reduced from about 2 weeks to an average of 7 days. The results of your test are emailed to Mr Penman and as soon as he receives your result, he will forward it on to you with a covering email. If the result is abnormal or there is no result because there was insufficient free fetal DNA in the sample, Mr Penman will contact you by phone and arrange to see you in person to fully discuss the result or repeat the sample, there is no additional charge for this. 3 in 100 women will require a repeat test.