Patient's question:
Doctor, my sister is going to have a prenatal test, and she wants to understand what the three bodies in triple screen screening refer to?Doctor's answer:
Down syndrome screening is a blood test conducted between the 16th and 20th weeks of pregnancy, which is around the fourth month of gestation. It primarily involves checking the median values of three chemical indicators—alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and estriol—to assess the risk of recurrence for three conditions: trisomy 21 (Down syndrome), trisomy 18, and open neural tube defects.If a specific test in the Down syndrome screening comes back positive, it only indicates a higher likelihood of recurrence for that particular condition, but it does not guarantee that the condition will actually occur. Its accuracy and specificity are not the highest.