23 weeks early?

23 weeks can carry out four-dimensional ultrasound examination of the fetus, more is to carry out some screening abnormalities diagnosis. First of all, in the second trimester of pregnancy is about 22-24 weeks of pregnancy, most of the prenatal hospitals will require pregnant women to routinely carry out ultrasound examination of abnormalities. During this period, it is necessary to measure the fetal biparietal diameter, head circumference, abdominal circumference and femoral length to assess whether the fetal growth and development conform to the gestational age. Secondly, it is necessary to screen for abnormalities in the general structure of the fetus. It is necessary to check whether the skull of the fetus is intact, whether there are abnormalities in the septum pellucida, falx cerebri, thalamus, bilateral ventricles, cerebellum and cisterna magna. It is also necessary to check whether the continuity of the bilateral orbits and upper lip of the fetus, whether the chest heart develops normally, the fetal heart beats, and whether the position of the four-chamber heart is abnormal. In addition to this, it is also necessary to check whether the fetus 'abdomen, stomach bubbles and intestinal tubes are dilated, as well as whether the kidneys and bilateral ureters are dilated, etc. Most of these cases can be carried out at 23 weeks of pregnancy, so it is not too early to carry out four-dimensional color Doppler ultrasound at 23 weeks.