Patient's question:
At week thirteen, the NT scan result was 1.3mm. At week sixteen, the Down syndrome screening result was 1:499. Is this a big problem? Is the risk of Down syndrome higher? Do I need to have more tests? I am 25 years old. I hope the doctors can help me. I am really worried.Doctor's answer:
Analysis of the condition: 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 performed by calculating the risk value based on the levels of AFP and HCG in the pregnant woman's serum, combined with the pregnant woman's age, weight, and gestational age. The critical value is 1/275. A value greater than this indicates high risk, while a value lower than this indicates low risk. The probability of having Down syndrome (DS) in the general population (under 37 years old) is 1/750.Recommendations: The purpose of the Down screen test is to determine the risk level of the fetus having Down syndrome by examining the pregnant woman's blood. If the Down screen test results indicate a high risk of the fetus having Down syndrome, further diagnostic tests such as amniocentesis or chorionic villus sampling should be conducted.