When you are pregnant for 20~24 weeks, you can have a big abnormality check. Pregnant mothers have such a feeling when they have a prenatal check-up. They feel that they are like learning from the scriptures and need to break through various difficulties along the way. Every check-up is scary, for fear that the child will have a little problem. After this check-up, it is necessary to start preparing for the next check-up. The check-up is really very important, because it is related to whether the pregnant mother can give birth to a healthy baby. In the process of our check-up, there will be a check-up called "big rejection".

This examination can be carried out at the age of 20 to 24 weeks. If the baby is too young, it is not fully developed, and some problems cannot be detected at all. If it's too late, the fetus is already big, and the activity space in the stomach is getting smaller and smaller, so it's not convenient for the doctor to do further examination, and once there is a problem, it will cause great physical and mental harm to the pregnant mother, so it's best to have a large-scale abnormality examination during the period of 20~24 weeks. Large-scale teratology examination is very important, because it can mainly check whether the child is deformed, but it can't guarantee the accuracy of 100%.

Accurately speaking, no matter which screening project the hospital is, it is impossible to achieve 100% accuracy. The diagnosis of large-scale malformation is mainly based on B-ultrasound images. If the fetal malformation changes little, doctors can't make a normal judgment. If the abdominal wall is thick during pregnancy, the sound transmission will be poor, which will also affect the final result. So once you find something suspicious, you must go to the hospital for further examination to ensure the accuracy of the results as much as possible.

But before we check, the doctor will tell us that the accuracy rate of large-scale abnormality is only about 70%, and we have always dared to guarantee the current situation. If some problems are found later, it is impossible to judge. Moreover, the large-scale abnormality examination is different from the chromosome examination, and if the child's chromosome finds a problem, it can't be seen. In order to give birth to a healthy baby, we must go to the prenatal examination on time and follow the doctor's advice.