Pregnant women a few weeks according to four-dimensional

Pregnant women generally need at least two four-dimensional ultrasound examinations during pregnancy. The first four-dimensional ultrasound examination is usually performed between 18 weeks and 24 weeks of pregnancy. This is mainly to rule out the development of fetal structure abnormalities, because at this time fetal movement is the most active, amniotic fluid is relatively more, and the fetal son's bones are not ossified, so it can be very good to check the fetal structure development abnormalities. The second time is usually around 32 weeks of pregnancy, he mainly needs to rule out whether there is an abnormality in the fetal heart. Because the fetal heart at this time has a certain size, it is easy to rule out abnormalities in the fetal heart through ultrasound examination.