Question
What is the risk of Down syndrome (Trisomy 21)?
Answer
Down syndrome, also known as Trisomy 21, is a common chromosomal abnormality that primarily affects children. Risk assessments are conducted based on the levels of alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) in pregnant women, combined with their age, weight, and gestational age. The critical risk value is set at 1/275, and any value higher than this is considered high risk. If the screening results indicate a high risk, it means there is a higher possibility of the fetus having congenital mental retardation. In such cases, it is recommended to undergo further tests like amniocentesis to confirm the diagnosis and ensure the health of the fetus.