The best time to get a non-invasive test is between 12-24 weeks of pregnancy. Non-invasive DNA testing is performed by drawing maternal venous blood and extracting free fetal DNA from the blood to screen the fetus for chromosomal disorders, mainly trisomy 21, trisomy 18 and trisomy 13. Fetuses with chromosomal abnormalities are combined with multiple fetal malformations and there is no effective treatment. Therefore, once a pregnant woman is screened for chromosomal abnormalities, it is recommended to terminate the pregnancy by induction of labor. Non-invasive screening is less risky and has a high accuracy rate of over 95%. The test is available for pregnant women who are at high or critical risk for Down’s syndrome screening and are over 35 years of age. Non-invasive testing can also be performed directly if financial conditions allow. In addition, non-invasive DNA testing does not require an empty stomach and results are available about 2 weeks after the blood is drawn.