The OSCAR test or ‘One-stop Clinic for Assessment of Risk for Fetal Anomalies’ is a test carried out in the first trimester of the pregnancy. It’s used to screen for the risk of fetal anomalies, particularly Down’s Syndrome (Trisomy 21). The test is optional and is available at all hospitals.
What Is OSCAR?
It involves a Nuchal Translucency (NT) scan and a blood test. If you wish to have an OSCAR test done, your doctor will schedule it usually between the 11th to 14th week of your pregnancy.
Depending on the results that determine whether you are at high risk or not, you can decide if you want further invasive testing such as CVS (Chorionic villus sampling).
OSCAR Test fee Singapore
The OSCAR test at different hospitals is priced differently in Singapore. These figures are estimates from mums in our community:
- Thomson Medical – OSCAR Test cost $310
- NUH – OSCAR Test cost $350
- MT Alvernia – OSCAR Test cost $330
This test is carried out in the first trimester to screen for the risk of foetal anomalies, particularly for Down Syndrome (Trisomy 21). It involves a Nuchal Translucency (NT) Scan and a blood test. The detection rate of Trisomy 21 by this method is about 90 per cent, with a false positive rate of 5 per cent.
- Procedure: Sample of mother’s blood and ultrasound scan
- Release period of result: About two to three working days
- Cost: ~$300+ at Thomson Medical Centre
You can find more information on the OSCAR Test at the NUH here.
Here’s everything you need to know about Down Syndrome
Down Syndrome affects one in every 1000-1100 live births worldwide. While there is no medical cure or manner of prevention for Down Syndrome, early intervention is possible. It all starts with a Down Syndrome screening test to find out whether a mother-to-be is at risk for having a baby with this chromosomal condition. We’ll tell you all about where to get Down Syndrome screening in Singapore in this article.
“While the Down Syndrome test is not compulsory in Singapore, about 90 per cent of pregnant women in Singapore take these tests,” says Dr Eunice Chua, Consultant Obstetrician and Gynaecologist at TLC Gynaecology Practice.
Tests differ according to the stage of your pregnancy. There is an initial screening during the first stage of pregnancy. This is then followed by diagnostic tests that ascertain the probability of Down Syndrome after the results of the screening test.
Other Types of Down Syndrome Screening In Singapore
Down Syndrome screening in Singapore — Ultrasound scans and blood tests can help assess if your unborn child may have Down Syndrome.
1. Nuchal Translucency (NT) Scan
Nuchal Translucency is an ultrasound scan that measures the width of the spinal cord at the back of the baby’s neck. It takes place between the 10th and 13th week of pregnancy. Doctors also call it the First Trimester Screening. Doctors usually recommend this assessment as part of the Oscar Test.
- Procedure: Via an ultrasound scan
- Release period of result: Immediately after the ultrasound scan is complete.
- Cost: $267.50+ at NUH
Additional information on the NT Scan at National University Hospital (NUH) can be found here.
2. Triple Test or Maternal Serum Screening
The Triple Test measures a set of three hormones (alpha-fetoprotein, HCG and Oestriol) in the blood of the pregnant mother. The test calculates a risk value based on the maternal age and the gestational age of the foetus at that time. It’s usually done around between 14th to 18th week of the pregnancy. Doctors also refer to it as the Second Trimester Screening. Its accuracy is only 65 per cent, which is why this test is less popular.
- Procedure:The medical practitioner takes samples of the mother’s blood.
- Release period of result: About seven working days
- Cost: $149+ at Singapore General Hospital (SGH)
You can find more information on the Triple Test or Maternal Serum Screening at the SGH here.
3. MaterniT21 Plus
MaterniT21 Plus is a new foetal DNA test launched in June 2013. It claims to have an even higher detection rate than the current first-trimester screenings.
Dr Ann Tan, a gynaecologist and obstetrician who chairs the obstetrics and gynaecology speciality interest group of Mount Elizabeth Hospital, claims that the
MaterniT21 Plus is 99 per cent accurate because it looks for the baby’s DNA and not the mother’s hormones.
Expectant mothers can do the new test as early as week 10 of pregnancy. These screening tests are usually done as early as possible, in case there is a need to terminate the pregnancy. However, this test does not replace the old blood test and nuchal scan.
- Procedure: The medical practitioner will take a sample of the mother’s blood.
- Release period of result: It takes about 10 working days or about two weeks after the samples go to the laboratory.
- Cost: $3,000+ at Parkway Health Laboratory
Click here for more information on MaterniT21 Plus.
Down Syndrome screening in Singapore — Through the analysis of the mother’s blood samples, doctors can assess the risk of Down Syndrome in the unborn child.
4. Non-Invasive Prenatal Tests (NIPT)
Available since late 2013, doctors can detect signs of Down Syndrome by obtaining the baby’s DNA through the mother’s blood sample.
Dr Chua explains, “NIPT uses the maternal blood test to detect DNA from pregnancy. There is 99 per cent accuracy with a low false-positive of 0.1 per cent.”
There are two types of NIPT in Singapore, namely Harmony Test and Panorama Test. The Harmony Test can take place from week 10 onwards of the pregnancy. Meanwhile, the Panorama Screening tests can be done from the ninth week.
The test should only be taken if a mother is classified as high-risk in first-level screening tests, which is about five per cent of all pregnant mothers.
- Procedure: The medical practitioner takes samples of the mother’s blood.
- Release period of result: It takes about 10 to 14 working days after sending the samples to a laboratory
- Cost: Harmony Test (~$1,200+), Panorama Screening (~$1,400+) at Thomson Medical Centre
*Check with your gynaecologist on which screening is suitable for you. Each doctor and hospital has varying facilities and your gynaecologist would be able to advise where to go for certain tests.
My Test Reveals High Risk Of Down Syndrome, So What Now?
If a screening test indicates a high risk of Down Syndrome, diagnostic tests may be performed to determine whether the baby actually has Down Syndrome. These are usually invasive options and pose a higher risk for both mother and baby.
Types of Diagnostic Tests
Amniocentesis
- Procedure: The medical practitioner will withdraw a sample of the amniotic fluid surrounding the baby through a needle inserted into the mother’s womb. This ensures the result’s accuracy is close to 100 per cent. The test results arrive in about two to three weeks.
- When: after 16 weeks of gestation
- Risk of miscarriage: 0.1 to 0.3 per cent or about one in 300 women
Chorionic Villous Sampling (CVS)
- Procedure: A sample of cells from the mother’s placenta is taken to analyse the baby’s genes, ensuring accuracy results of close to 100 per cent. Expect results within 48 hours to one week.
- When: between weeks nine and 14 of pregnancy
- Risk of miscarriage: approximately one in 200
Percutaneous umbilical blood sampling (PUBS) or Cordocentesis
- Procedure: This test involves taking a blood sample from a vein in the umbilical cord and examining blood cells for chromosomal defects. But due to its significantly higher risk of a miscarriage as compared to the previous two diagnostic tests, this is only offered as an alternative option. They employ this test when there are unclear test results from other methods.
- When: after 18 weeks of gestation
- Risk of miscarriage: 1.4 to 1.9 per cent
Who Are At Higher Risk?
The risk of Down Syndrome is directly related to the mother’s age. The older the mother, the higher the risk. For example, a 20-year-old woman has a one in 1,500 risk of having a baby with Down’s syndrome. In comparison, a 35-year-old woman has a one in 270 risk.
Additionally, about one in 100 women with a previous baby with Down Syndrome will have another. As Dr Chua points out, “Older mothers, history of Down Syndrome in a previous pregnancy or family history of Down Syndrome [and] history of recurrent miscarriages which could be due to translocation abnormalities (i.e. scrambled chromosomes) put the risk of Down Syndrome at a higher level.”
Dr Chua also notes that there is a slightly higher risk in boys than girls, too.
There is no treatment or prevention method available for Down Syndrome. But with the available Down Syndrome screening tests in Singapore, fears may be allayed and parents are able to make appropriate choices for their family.
Mums, which Down Syndrome screening test did you choose? Do share your reasons for going for testing below!
Reference:
Palomaki, Glenn, Lee, Jo Ellen, et.al., Nature.com, Genetics in Medicine (2009) 11: 669–681. Web 17 August 2009.
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