The leg is not short at 30 weeks when the femur length is 57mm, it can be reviewed under doctor’s supervision. Femur length (FL) refers to the length of the fetal thigh bone. Ultrasound monitoring of fetal femur length, biparietal diameter and abdominal circumference during pregnancy can be used to understand fetal development and also to assess fetal size. Fetal femur length at 30 weeks of gestation is normally between 52-61mm, so when the ultrasound suggests that the femur length is 57mm the fetal legs are not short, you can dynamically review under the guidance of the doctor. During pregnancy, it is necessary to follow the doctor’s instructions to take obstetrical examination on time, and appropriately increase the amount of food containing protein, vitamins, calcium, iron and other nutrients, such as meat, dairy products, eggs, and fresh vegetables and fruits, in order to satisfy the needs of the growth and development of the fetus. Fetal movement count is also performed at 30 weeks of pregnancy to evaluate the intrauterine condition of the fetus, and when abnormalities such as decreased fetal movement occur, it is necessary to go to the hospital in time.