Non-invasive is short for non-invasive DNA, and the test is usually available from 12-22+6 weeks of pregnancy, usually no later than 26 weeks of pregnancy. Non-invasive DNA testing involves the extraction of maternal peripheral venous blood and sequencing of fetal DNA to detect whether the fetus has any of the three major chromosomal disorders, namely trisomy 21, trisomy 18 and trisomy 13. There is a timing requirement for the non-invasive DNA test, which is usually available from 12-22+6 weeks of pregnancy. If the pregnant woman requests it, noninvasive can be done in late pregnancy, but the results of noninvasive in late pregnancy have little clinical guidance significance; the results of noninvasive DNA generally come out in two weeks, because if there is a problem with the results of noninvasive DNA testing, amniocentesis needs to be completed before 24 weeks; if the noninvasive is performed more than 26 weeks, the results will be returned at 28 weeks and enter the perinatal period, so if there is no ultrasound abnormality, the guidance has little significance . It should be noted that non-invasive does not require fasting, you can have your blood drawn after breakfast, but you should try to avoid stimulating food and avoid strenuous exercise before the blood draw, you can sit still for more than 30 minutes before the blood draw, otherwise the results may be affected.