Do four-dimensional color Doppler ultrasound need to make an appointment in advance

Do four-dimensional color Doppler ultrasound need to make an appointment in advance. Because four-dimensional color Doppler ultrasound needs to be examined in a 3A hospital, and do four-dimensional color Doppler ultrasound takes a long time, about 40-60 minutes. The best time to do four-dimensional color Doppler ultrasound is between 22-28 weeks of pregnancy. If this time period is exceeded, the fetal development cannot be observed well. Four-dimensional color Doppler ultrasound is to dynamically observe the fetal head, limbs and internal organs, especially whether there is abnormality in cardiac development during intrauterine activities. It is an important screening item during pregnancy. Do four-dimensional color Doppler ultrasound best to wear loose, easy to wear shoes and clothes, but also bring a small snack, in the process of doing if the fetus does not move, you can go out for a while or eat snacks to induce fetal movement.