What is Tang screening test?
Down screening is a type of prenatal screening for pregnant women that can detect whether the fetus has chromosomal abnormalities such as Down syndrome. This examination is performed in the first trimester, including blood testing at 13-14 weeks of pregnancy and B-ultrasound examination at 18-22 weeks of pregnancy. It is widely used in clinical practice because of its safety, non-invasiveness and high accuracy.
Gestational age selection
The most accurate time for Tang screening examination is to conduct blood test at 13-14 weeks of pregnancy and B-ultrasound examination at 18-22 weeks of pregnancy. Among them, blood testing can detect the specific risk of chromosomal abnormalities and provide a basis for further diagnosis. B-ultrasound examination can directly observe the fetal development and organ structure, including the measurement of characteristic indicators such as allantois and neck cysts, so as to accurately diagnose whether there are chromosomal defects such as Down syndrome and related congenital malformations.
Pregnancy period selection
It is more accurate to perform a Tang screening test in the first trimester, because the Tang screening test in the first trimester uses the cell-free DNA produced by the natural death and metabolism of early cells in the amniotic cavity, combined with high-throughput sequencing technology for screening, so it is highly accurate. In addition, the Tang screening examination in the third trimester is not conducive to the standard measurement and diagnosis of structural malformation characteristics through B-ultrasound examination because the size of the fetus is getting larger and larger.
Notes
Before undergoing Tang screening examination, women need to understand the purpose, process and related risks of the examination, and choose a regular hospital and fully qualified medical personnel for examination. In the early stage of the examination, women need to actively maintain a good mentality and nutritional status and avoid flying, strenuous exercise and sexual life. At the same time, in the later stage of the examination, women should make reasonable and responsible medical decisions based on the examination results and doctor\’s suggestions, after sufficient thinking, understanding and communication.
Summary
Tang screening is a very important screening method that can detect certain genetic problems early, prevent adverse consequences, and improve the health quality of newborns. Therefore, in the first trimester, pregnant women must be familiar with the examination process and precautions, and choose the appropriate time and hospital for examination to improve the accuracy and reliability of the examination. Only by comprehensively considering various factors can we make reasonable and responsible medical decisions to protect the health of ourselves and our fetuses.
