The best time for us to do an ultrasound in early pregnancy is after menopause has been detected and when the HCG test, which is a positive pregnancy test, is actually needed to determine whether it is intrauterine or extrauterine, so it can be done at about 5 or 4 weeks of menopause. Another most important test in early pregnancy, after it has been determined that the pregnancy is intrauterine, is the early pregnancy screening test, commonly known as NT test, from 11 to 14 weeks. This test can help us to detect serious structural abnormalities and chromosomal abnormalities at an early stage, and this is the best time for early pregnancy screening. The NT of early pregnancy ultrasound, in most of our existing hospitals, obstetricians will arrange the examination according to the routine, maybe some township health hospital doctors do not know much about this, but all pregnant mothers must remember that this stage still should not be missed, because this is one of the best real time for the baby examination to screen out malformations.