Ultrasound BPD refers to the fetal biparietal diameter. During pregnancy, you need to go to the hospital regularly for obstetric ultrasound examination, not only to check the fetal biparietal diameter, but also to check the fetal head circumference and femur length and other indicators to determine the development of the fetus, if the fetal indicators are within the normal range, there is no problem and you can not worry too much. If the fetus is large or small, you need to pay attention to it and go to the hospital actively to check whether there is fetal dysplasia, and if the double parietal diameter is large, it may be that the pregnant woman’s blood sugar is elevated and there is a huge baby. A few may have pathological conditions, such as fetal hydrocephalus, which require relevant examination, and a small fetal biparietal diameter should be observed for fetal growth restriction.