Nasal bone not shown at 22 weeks may be related to physiological reasons such as fetal body position covering the face, which is not a big problem, or pathological reasons such as chromosomal abnormality, which is a serious problem and needs to be analyzed specifically. 1. Physiological reasons: the fetal arm obscures the face during the examination, resulting in the nasal bone not being displayed, generally not a big problem. The examination can be conducted again, and before the examination, you can exercise moderately and rotate the fetal position to see if you can see it. 2. Pathological causes: 22 weeks nasal bone not seen to show may be caused by chromosomal abnormalities, common 21 – trisomy, need to do non-invasive DNA or amniocentesis, if the diagnosis of 21 – trisomy, at this time is more serious, the need for timely induced termination of pregnancy. During pregnancy, you should keep a happy mood, pay more attention to rest, and go to the hospital regularly for maternity checkups. Consult your doctor when problems are detected, and consider terminating the pregnancy if necessary.