What is the meaning of the femur length?

Patient's question:

No

Doctor's answer:

Femur length, also known as the length of the thigh bone, is often used in obstetric ultrasound examinations to monitor fetal development. The femur length is also one of the key data used to calculate the fetal weight during pregnancy. As the gestational age increases, the value of the femur length gradually increases, indicating that both the length and weight of the fetus are gradually growing.