There is no such thing as a normal value. The risk rate screening for open neural tube defects, which currently has a stage value of 1:275, is not a statement of normal or abnormal. This is only a preliminary screening and the significance of the value obtained does not mean that there is a problem or that there is no problem, but rather that it indicates the magnitude of the risk of an abnormality. If the test is high risk, it does not mean that there is definitely a problem, and low risk does not mean that it is completely normal. Of course, if the test is low risk, the chance of having an open neural tube defect is relatively low. Continue to take other normal pregnancy tests, and as long as all other pregnancy tests are normal, it does not matter. If the test is high risk, that means the risk of abnormalities is higher and further tests are needed to clarify. Amniocentesis or non-invasive DNA testing can be done to determine if there is a problem, and these can be done to confirm the final diagnosis.