Wednesday 30 July 2014

Latest tests for Down's Syndrome and other genetic abnormalities

One of the greatest concerns for a pregnant woman is knowing whether her child will be normal. In this day and age when more women are getting pregnant at a later age especially in Singapore, this is of an even greater concern.
Fortunately, more advances have enabled us to do these tests at an earlier and earlier stage of the pregnancy. We are now able to allay a patient's fears even at 9 weeks of pregnancy!
The latest blood tests which now almost always replace amniocentesis (tapping of the baby's water bag) include the Harmony Test and the Panorama Test. These are non-invasive prenatal tests done as early as 9 weeks. During pregnancy some of the baby's DNA passes into the mother's blood stream. This DNA can be examined through a simple blood test. This is a great test since traditional tests such as amniocentesis or chorionic villus sampling all carry a slight risk of miscarriage. The Panorama test is about 99.5% accurate, however it is still a screening test and if the result comes back as positive the mother will still have to go through an amniocentesis.
The genetic conditions that are tested with the Panorama include Down's Syndrome (T21), Edwards Syndrome (T18), Patau's Syndrome (T13), Certain sex chromosome abnormalities such as Turner's Syndrome, Kleinefelters Syndrome, Triple X, Triploidy. The sex of the baby may also be known if requested.
The greatest drawback to these tests is the cost ranging from S$1500 to S$2000. I would normally advise these tests if the original Oscar test (traditional blood test for Down's Syndrome) comes back as positive or the patient is over 35 years. Of course it can be done for any patient upon request.

2 comments:

  1. What is my panorama test result is good but my Oscar scan indicate no nasal bone and put me in high risk of 1:281 of down syndrome? All other markers such as NT are normal.

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  2. Hi Doc. Given the completeness of test and price, would you recommend Harmony or Panorama more? I am 30 years old and currently at my 8 weeks of pregnancy, first child. I had history of PCOS but as far as I know no other known members of my extended family have had any fertility or chromosomal dysfunction. Thanks in advance!

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