The timing of Down’s syndrome screening is also very important. Usually what we call Down’s syndrome screening is done in the middle of pregnancy, while in recent years it can also be done in the early stages of pregnancy. The best time for Down’s syndrome screening is between 11 and 14 weeks of gestation. The main purpose of Down’s syndrome screening is to somewhat avert the risk of fetal congenital dysmorphism. Doctors recommend that mid-pregnancy Down’s syndrome screening be performed between 15 and 20 weeks of pregnancy, with the best time being between 16 and 18 weeks. Early or late screening can affect the accuracy of the results. If the hospital report identifies a high-risk condition during the screening process, the doctor will usually recommend an amniocentesis. If a pregnant woman misses a screening test, she cannot make up the test and can only undergo amniocentesis, which is a procedure to screen for Down’s syndrome by drawing amniotic fluid. Down’s syndrome screening involves drawing the mother’s venous blood and does not require an empty stomach ~ you need to bring an early ultrasound for verification, and you must also bring a recent ultrasound