Harmony prenatal test – the screen for chromosomal abnormalities
THE Harmony prenatal test is non-invasive prenatal testing, also called NIPS (non-invasive prenatal screening), which is used in assessing the risk of a foetus being born with some genetic abnormalities. The test is referred to as non-invasive because, unlike prenatal tests that use cells taken from inside the pregnant woman’s placenta, only a sample of the mother’s blood is required. It poses no risk to the unborn child.
The Harmony test can be done as early as the 10th week of pregnancy, and is done by analysing fragments of the baby’s DNA that are present in the mother’s blood, explained Tobi-Gail Smith, marketing and technical representative at Caribbean Genetics (CARIGEN) at The University of the West Indies.
“The Harmony test screens for chromosomal abnormalities that indicate conditions such as Down’s syndrome, Patau syndrome, and Edward’s syndrome, as well as possible sexual abnormalities. It can also tell the sex of the baby from as early as 10 weeks,” she said.
Smith noted, however, that the Harmony test is a screening test, and if chromosomal defects are observed, then confirmatory tests would be done before a diagnosis is given. These confirmatory tests are ‘invasive’, as they would be performed on samples drawn from inside the placenta, where there is a higher concentration of foetal DNA cells.
CARIGEN provides Jamaican mothers with the option of having the Harmony screening done through a partnership with the American Harmony company. Blood samples are drawn locally, and then sent to the US for testing, and patients can expect results within seven to 10 business days.
“The test is usually requested by physicians in Jamaica for various reasons, but in a lot of western countries the test is routinely done,” Smith said. “A referral, however, is not required to do the Harmony test. We offer the service by appointment on Tuesdays and Thursdays.”
Who is at risk for genetic abnormalities?
Though any pregnancy can result in a child being born with a genetic abnormality, consultant obstetrician-gynaecologist Dr Mandi Elliot shared some factors which may contribute to a foetus being more at risk.
“If the mother has previously given birth to a genetically abnormal child, if the parents are closely related, if the mother has had previous miscarriages, or if either parent has done tests which show that they are a carrier of a genetic disorder, these increase the risk of a foetus having one,” she said.
“The risk is also higher among women who get pregnant after the age of 35, and in families that have a history of genetic abnormalities.”
While the Harmony test is not a required test in Jamaica, it is definitely one you can consider doing. An early diagnosis can mentally prepare you for what to expect when your baby arrives.
