NIH Websites Are Changing

NIH is moving the launch of its new website to the fall to ensure the best possible experience for everyone who relies on our websites for health information, research, funding opportunities, and other resources.

Get the Latest Updates and FAQs

Fetal Growth Calculator - Definitions

Definitions

  • Gestational Age:
    Age of the pregnancy, in completed weeks and days   
  • Biparietal Diameter (BPD):
    Distance between the two parietal bones of the fetal skull (outer to inner), in millimeters   
  • Head Circumference:
    Measurement of the fetal head at its widest, in millimeters   
  • Abdominal Circumference: Measurement of the fetal abdomen, in millimeters   
  • Femur Length: Length of the fetal thigh bone, in millimeters   
Back to Calculator		 Illustration of the four measurements on a baby’s body: femur length, abdominal circumference, head circumference, and biparietal diameter.
top of page BACK TO TOP