Question
What is the probability of a child having Down syndrome?
Answer
Down syndrome, also known as trisomy 21, is a condition where the patient has an extra chromosome 21, one more than the normal pair. The Down syndrome screening is conducted by analyzing the levels of AFP and HCG in the pregnant woman’s serum, combined with her age, weight, and gestational age to calculate the risk value. The critical value is 1/275. A value greater than this indicates high risk, while a value below it suggests low risk. The general population (under 37 years of age) has a 1 in 750 chance of having Down syndrome (DS). If the screening result is high risk, it is recommended to perform amniocentesis. However, even with a high risk, it does not necessarily mean the child has Down syndrome. For safety’s sake, it is still recommended to undergo DS screening! Children with Down syndrome have severe intellectual disabilities, cannot care for themselves, and are accompanied by complex cardiovascular diseases. They require long-term care from family members, which can impose a significant emotional and financial burden on the family.