At 30 weeks of pregnancy the biparietal diameter of 86mm is slightly larger and the femur length of 54mm is normal. The average value of the biparietal diameter at 30 weeks of pregnancy is 7.83±0.62cm, and the biparietal diameter of 8.6cm is slightly larger, while the average value of the femur length is 5.77±0.47cm, and the femur length of 5.4cm is within the normal range. However, due to the ultrasound examination and the machine and the doctor’s different there will be some deviation, need to be combined with the fetal heart, abdominal circumference and other results to make a comprehensive judgment, basically is relatively normal. After 28 weeks of pregnancy belongs to the late stage of pregnancy, this stage of fetal growth and development is relatively fast, it is recommended that pregnant women once every two weeks for maternity examination, diet to fresh fruits and vegetables, high quality protein food, avoid smoking and alcohol.