This test is mainly non-invasive and poses no obvious risk to pregnant women and fetuses. However, it should be noted that NT examination is only a screening tool, and it cannot provide clear diagnostic information. If the NT test results are abnormal, further genetic testing, such as amniocentesis or chorionic villus biopsy, can be suggested to confirm whether there is chromosome abnormality. If you have any questions about health or medical problems during pregnancy, you'd better consult your doctor or obstetrician, who can provide you with more detailed and personalized guidance and advice.