Question
When is the best time to perform a Down syndrome screening? What tests can detect fetal developmental abnormalities?
Answer
Down syndrome screening is a method that involves taking a pregnant woman’s serum and measuring the concentration of alpha-fetoprotein and human chorionic gonadotropin in the maternal serum, combined with information such as due date, age, weight, and gestational weeks to calculate the risk of giving birth to a baby with Down syndrome. It is recommended to undergo Down syndrome screening between the 15th and 20th week of pregnancy. If the screening results show a high risk, further tests such as amniocentesis and fetal chromosome testing may be needed to confirm whether it is Down syndrome. In addition, it is suggested to have a high-resolution ultrasound examination between the 21st and 27th week of pregnancy to help rule out major fetal organ malformations.