Non-invasive test to screen for Down syndrome

PHOTO: Non-invasive test to screen for Down syndrome

SINGAPORE - A new non-invasive test to screen yet-to-be-born babies for Down syndrome is now available in Singapore hospitals.

Previously, doctors had to insert a needle deep into the mother's belly and draw fluids to test them for indicators of Down syndrome, in a test called amniocentesis. But this carries "a small risk of miscarriage", said Associate Professor Tan Hak Koon, president of the College of Obstetrics and Gynaecology (O&G) of Singapore, at a global medical conference held here till Tuesday.

The new test, called the Non-Invasive Prenatal Test (NIPT), saves mothers that risk. Doctors just need to draw blood from the mother's forearm and test the sample, which contains foetal DNA fragments, for Down syndrome, which causes growth delay and intellectual disability.

Doctors warned though that the results of the new test must be interpreted with caution or else mothers might terminate their pregnancies wrongly.

"Women still need to go for amniocentesis to determine if their baby would be born with Down syndrome. NIPT is a good first- level test, but mothers should not be making decisions based on that information alone," said Adjunct Professor George Yeo, chief of obstetrics at KK Women's and Children's Hospital (KKH).

The non-subsidised test has been available in KKH and Singapore General Hospital (SGH) since late last year. The $2,000 NIPT should be taken only if mothers are classified as high-risk in first-level screenings - about 5 per cent of pregnant mums. But high-risk mothers can skip NIPT and go straight to amniocentesis, which is government-subsidised.

So far, 43 high-risk pregnant women have taken NIPT in KKH and SGH. All tested negative.

Said Mrs Eve Tan, 35, who became a mother recently: "If I am high-risk and if there is a more painless and less risky test, I would opt for it."

Women are also reminded to go for First Trimester Screening, a subsidised test. It picks up indicators of Down syndrome and structural abnormalities but can be done only in the 11th to 14th week of pregnancy.

The doctors were speaking on the sidelines of a conference combining the 5th College of O&G Singapore Scientific Congress and the 10th anniversary of the International Society of Ultrasound in O&G Outreach course.

kashc@sph.com.sg

This article was published on April 5 in The Straits Times.

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