During your pregnancy, your healthcare consultant will offer various tests to help you assess your health.
As part of your antenatal care, you will be given to the option to test for Down syndrome, a rare genetic condition that affects physical and mental development. Some genetic conditions run in families. Others, like Down Syndrome, typically do not. They can happen in any pregnancy. Although the risk of Down syndrome increases with age, most babies born with Down syndrome are born to women under 35.
When you’re pregnant, your blood contains fragments of your baby’s DNA. The Harmony Test is a type of test that analyses this DNA in a sample of your blood to assess the risk of:
For all women
Traditional screening tests can miss as many as 15% of Down Syndrome cases in pregnant women. Harmony was developed to be a more accurate prenatal Down Syndrome screening test for all women, regardless of age or risk. It is a new DNA-based blood test that has been extensively tested in pregnant women both over and under 35.
A more accurate test
Conventional screening will detect approximately 70-80% of pregnancies with Down syndrome. The Harmony test will detect over 99%.
Harmony has a false positive rate of less than 0.1% compared to the 5% with conventional screening. This means that the Harmony test detects more pregnancies with Down syndrome but also reduces the risk of unnecessary amniocentesis.
Harmony Test requires a single blood sample from your arm and can be done as early as 10 weeks or later in pregnancy. Results are usually available within a week. Other commonly used tests for Down syndrome are performed later in pregnancy and require multiple clinic visits.
Minimises need for follow-up tests
The greater accuracy and low false-positive rate of Harmony compared to the traditional tests minimises the number of high risk results. Therefore fewer women will need follow up testing using an invasive procedure, such as amniocentesis.
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 of missing copy of the X or Y chromosomes, including Turner and Klinefelter syndromes. (This is only available for singleton pregnancies).
Does a low risk result mean that the baby does not have Down syndrome
No, any screening test carries a risk of a ‘false negative’ however the risk of this happening with the Harmony is much lower than with conventional Down screening.
If I have a high risk result does that mean that the baby’s chromosomes are abnormal?
No, not necessarily. It means that there is a higher risk and you will be offered the option of amniocentesis to assess the chromosomes directly. You will be offered support and counselling to help you reach that decision.
What if I have twins?
The Harmony Non Invasive Prenatal Test and technology can also be applied to twin pregnancies but is not suitable in the case of a vanishing twin.
Will I always get a result?
3 out of 100 women will require a repeat test. We receive a result in approximately two thirds of these samples. Patients will not be charged if we are unable to obtain a result.
The test result will give you a clear answer about the risk to your pregnancy of having any of the genetic conditions included in the test. All results will be given to you by the Clinic and will be interpreted in the context of your medical details and family history. You should continue with your usual scan appointments before and following testing.
Non-invasive prenatal testing based on cell-free DNA analysis is not considered diagnostic.
Visit The Surrey Park Clinic for private Prenatal Care
At the Surrey Park Clinic we offer the new more accurate Harmony Test for Down Syndrome and ultrasound scanning without referral, for peace of mind during your pregnancy.
Call 01483 454 016 to arrange an appointment or complete the quick contact form: