Biparietal diameter and femur length standards
Disease description:
I'm going to the hospital for a prenatal checkup tomorrow, so I'd like to first understand what the standard measurements are for fetal biparietal diameter and femur length.
Doctor's answer (1)
Dr. Zhao Xiaodong
Biparietal diameter (BPD) and femur length (FL) are commonly used indicators in prenatal ultrasound examinations to assess fetal growth and development. The biparietal diameter refers to the maximum width between the two sides of the fetal head, also known as the fetal head's transverse diameter. As gestational age increases, the biparietal diameter gradually enlarges, reaching an average value of 90–94 mm at 37–40 weeks of gestation. Femur length refers to the length of the fetal thigh bone and is an important parameter for evaluating lower limb development. Similarly, femur length increases with gestational age, averaging approximately 70–75 mm at 37–40 weeks. During prenatal ultrasound examinations, physicians typically measure both biparietal diameter and femur length together to comprehensively evaluate fetal growth and development. If abnormalities in BPD or FL are detected, further investigations may be required to determine the underlying cause.
