Patient's question:
NoDoctor's answer:
Down syndrome, also known as Trisomy 21, refers to a condition where the patient has an extra chromosome in the 21st pair (while the normal number is one pair). Down syndrome screening is calculated by measuring the levels of AFP and HCG in the pregnant woman's serum, combined with the pregnant woman's age, weight, and gestational age to determine the risk value. The critical value is 1/275. A value greater than this indicates high risk, while a value lower than this indicates low risk. The purpose of the screening test is to determine the risk of the fetus having Down syndrome by analyzing the pregnant woman's blood. If the screening test results indicate a high risk of the fetus having Down syndrome, further confirmatory tests such as amniocentesis or chorionic villus sampling should be conducted.