The femur length of the fetus at 24 weeks of pregnancy is usually around 4.8cm, which actually means the length of the thigh bone. Doctors usually check through ultrasound or color ultrasound of pregnant women to determine whether the fetus is developing normally. At this time, the fetus can reach about 30cm in length, weighing about 630g, and the abdominal circumference of the pregnant woman is about 20cm. The brain is developing very rapidly at this stage, and it is also starting to have a certain sense of taste. Since every baby has different developmental status and different genetics, there will be some differences in height, weight, femur, biparietal diameter and humerus development. If the fetal development does not differ much from the standard values, there is no need to worry too much. If the fetal femur is found to be short, it may be due to genetic factors that cause the fetal femur to be short. You can enhance nutrition and supplement with high quality protein as well as calcium to promote fetal bone development, and do ultrasound tracking dynamically. Avoid excessive calcium supplementation to avoid premature placentation. If the overall fetal size is smaller than normal in combination with fetal biparietal diameter or uterine height and abdominal circumference, intrauterine growth restriction is considered and the cause needs to be identified and treated, but if the femur is significantly short, fetal chromosome karyotyping is needed.