Many female friends will regularly go to the hospital for examinations after pregnancy, including Down syndrome screening tests and non-invasive tests. For the sake of themselves and the fetus, many people will do it. But there are some people who don't know about Tang Xi and only do non-invasive work. Do we still need to do Tang screening after doing non-invasive?
There are actually many items for pregnant women to undergo prenatal examinations, and the results obtained from each examination item have a fixed indicator. Sometimes the same inspection indicators can be used to select different inspection items. Sometimes the results of these inspection items may be the same, while others may have significant differences. For example, there is a difference between Tang screening and non-invasive examination. But the accuracy of non-invasive examination is higher than that of Tang screening. So after doing non-invasive, there is no need to do Tang screening again.
At present, in clinical medicine, Down syndrome screening mainly includes trisomy 18 and trisomy 21 syndromes. In addition, it can also check the risk of neural tube defects in fetuses. The non-invasive examination mainly excludes trisomy 21, trisomy 18, and trisomy 13 syndrome. Although the two types of examinations cannot replace each other, after non-invasive treatment, the condition of the fetus can be well judged, so it is generally not recommended to undergo Down syndrome screening examination again.
In addition, non-invasive examination is usually conducted between 14 and 24 weeks of pregnancy, which can detect whether the baby is at risk of malformation or has other diseases. The Down syndrome screening test is conducted from 14 to 20 weeks of pregnancy. Due to the high accuracy and high cost of non-invasive examination results, doctors usually recommend performing non-invasive screening directly if it is necessary. So if you have done non-invasive work, you don't need to do Tang screening.
