Patient's question:
I am currently three months pregnant and everything has been checked and is normal. When is the best time to do the mid-pregnancy Down syndrome screening?Doctor's answer:
The second-trimester Down syndrome screening is a prenatal screening test, not a diagnostic test. Down syndrome screening is a method that involves extracting the pregnant woman's blood to test the concentration of alpha-fetoprotein and human chorionic gonadotropin in maternal serum, and then calculating the risk coefficient of the fetus suffering from trisomy 21 based on the pregnant woman's estimated due date, age, weight, and gestational age at the time of blood collection. The optimal time for second-trimester Down syndrome screening is at 16-18 weeks of gestation, but it can generally be performed between 15-20 weeks.