Fetal leg length mainly depends on the value of femur length in the ultrasound examination index. Fetal femur length reflects the length of the thigh bone, and in a certain sense, it also represents the height of the fetus, but it is not a decisive factor. Generally speaking, you can start to measure the length of fetal femur through ultrasound after 14 weeks of pregnancy, and if you find that the length of fetal femur is abnormal after ultrasound examination, the doctor will point out the abnormal value and analyze the reason according to the professional point of view, so you don’t need to be nervous if the doctor doesn’t mention the length of fetal femur specifically after the examination. Besides reflecting the development of fetal leg bones, femur length is also one of the important data for calculating fetal weight during pregnancy. As the weeks of pregnancy increase, the value of femur length will also increase gradually, which indicates that the length and weight of the fetus are gradually increasing. In order to avoid poor growth and development of the fetus, during pregnancy, we must pay attention to the reasonable supplementation of nutrients, not too biased, picky eating, not to mention excessive tonic, usually also pay attention to rest, sleep should be enough to ensure the health of pregnant women as well as the normal development of the fetus.