Ultrasound at 30 weeks is mainly to check fetal development, amniotic fluid, placenta, fetal position, and whether there is umbilical cord around the neck, the details are as follows: 1, amniotic fluid: at this time, you can check the depth and index of amniotic fluid, to see whether there is too much amniotic fluid, amniotic fluid is too little, etc.; 2, fetal development: to check whether the fetus is in line with the month of gestation, and if fetal development is lower than the gestational week, consider the possibility of fetal growth restriction If the development of the fetus is lower than the gestational week, the possibility of fetal growth restriction should be considered. If the fetus is large, dietary adjustments are also needed to prevent the occurrence of giant children; 3, umbilical cord: check whether there is umbilical cord around the neck, umbilical cord torsion, and need to know the condition of the placenta and its position; 4, fetal position: check whether there is abnormal fetal position, the normal fetal position is the cephalic position, and if there is a breech position, the doctor can give positive corrections under the assessment and guidance of the doctor. In addition to checking the ultrasound, the 30-week pregnancy checkup also needs to listen to the fetal heart, measure blood pressure, weigh, measure uterine height, abdominal circumference, and make clear whether the pregnant woman’s lower limbs have edema, and so on.