Which of the high risks in Tang Si is the most terrifying?

Down screening is a common prenatal screening method used to detect whether the fetus carries chromosomal abnormalities, such as Down syndrome. In Tang screening, a number of indicators are measured, including serological indicators, ultrasound indicators and comprehensive indicators. So, among these indicators, which one is the most dangerous? First of all, serological indicators are one of the most commonly used indicators in Tang screening. By measuring the content of certain substances in the blood of pregnant women, it can be inferred whether there are chromosomal abnormalities in the fetus. Common serological indicators include free β-human chorionic gonadotropin (Free β-hCG), pregnancy-associated plasma protein A (PAPP-A), etc. Abnormal values ​​in these indicators may mean that the fetus is at risk for chromosomal abnormalities. However, serological indicators cannot directly determine whether there is a chromosomal abnormality and can only be used as a risk assessment indicator. Therefore, although abnormalities in serological indicators may cause concern to parents, they do not necessarily mean that the fetus is truly at high risk. Secondly, ultrasonic indicators are also one of the commonly used indicators in Tang screening. Ultrasound examination can observe the structure and shape of the fetus and determine whether there are chromosomal abnormalities. Common ultrasound indicators include nuchal translucency (NT) and nasal bone length (NB). Under normal circumstances, the fetal neck is less transparent and the nasal bones are longer. Abnormal neck transparency and nasal bone length may indicate a risk of chromosomal abnormalities in the fetus. Compared with serological indicators, ultrasound indicators can directly observe the structure of the fetus and are therefore more accurate. However, abnormal ultrasound indicators are only a risk assessment indicator and cannot directly determine whether there is a chromosomal abnormality. Finally, the comprehensive index is the result of comprehensive consideration of serological indicators and ultrasound indicators. By comprehensively evaluating fetal serological indicators and ultrasound indicators, we can more accurately determine whether the fetus is at risk of chromosomal abnormalities. The calculation method of comprehensive indicators is relatively complex and needs to be combined with specific algorithms and models. However, the comprehensive indicator is only a risk assessment indicator and cannot directly determine whether there is a chromosomal abnormality. To sum up, the serological indicators, ultrasound indicators and comprehensive indicators in Tang screening all have certain risk assessment capabilities. However, no matter which indicator is abnormal, it cannot directly determine whether the fetus has chromosomal abnormalities. The purpose of TangScreen is to provide a preliminary risk assessment, not a definitive diagnosis. Therefore, parents should remain rational when accepting Tang screening results and combine other examination methods for further diagnosis and evaluation. The most important thing is to consult a professional doctor promptly to obtain scientific and accurate advice and guidance.