What is Down's Syndrome ?

Q: What is Down's Syndrome?
A: It's a birth defect occuring in about 1 of every 1000 births, in which an extra N0. 21 chromosome is present in the developing foetusfro the time of conception.

Q: What are the impacts that can cause to the baby?
A: It may cause mental retardation (often mild to moderate), may have visible physical characteristics & some may have medical problems eg. heart defects.

Q: Who will have higher possibilities to give birth to Down's Syndrome babies?
A: In theory, posibilities rises with an increse in maternal age pregnancies or history of Down's Syndrome. Maternal age (35 & above) has traditionally been used as a cut-off point for performing a prenatal diagnosis to detect Down's Syndrome in pregnant women. However, 80% of Down's Syndrome babies are born to women who are less than 35 yrs old.

Q: What is Double Test/ Triple Test?
A: It's a blood test that measures substances in the pregnant mother's blood.
Substances like AFP (Alpha-feto protein), free β-hCG (free beta-human chorionic ganodotrophin) & uE3 (conjucgated oestrial). The level of these substances are used in combination with the woman's ageto determinethe statistical risk of Down's Syndrome in the baby. The level of AFP alone is use to determine if there is an increased risk of neural tube defect such as anencephaly or spina bifida.

Q: How is the risk can be calculated?
A: Babies with Down's Syndrome tend to produce less AFP than normal babies, whereas babies with neural tube defect produce much greater levels of AFP. β-hCG level tends to be higher when Down's Syndrome is present. Anaylsis & estimation of the risk is performed by using a computer& reported as a numerial risk based on the determined blood markers, age & gestation of the fetus.

Q: What does the result of a maternal serum marker screening mean?
A: The result describes the risk of giving birth to Down's Syndrome baby relative to the average pregnant women, reported as a numerical risk compared to a risk cut-off. The risk of 35 yrs old women (1:250) has ben used as the risk cut-off, where if a patient's risk is > 1:250, the serum is reported positive.

Q: What are further tests that will be offered if a patient test result is positive?
A: If the patient's test results is positive, it does not necessary mean that the baby has the disorder, but it means that the doctor will suggest the patient with some additional test, eg. Amniocentesis.

Q: What is Amniocentesis & what will it show?
A: Amniocentesis is a test in which the doctor obtains a small sample of fluid that surrounds the developing foetus. That fluid can be use to diagnose Down's Syndrome. Result will be shown in 2 - 3 weeks later. A small degree of risk may involved.

Q: What is the best time for Down's Syndrome screening?
A: Blood test should be done between 14-18 weeks of pregnancy. Unreliable result may be obtained if the blood sample is taken too early during the pregnancy.