Femur length

Fetal femur length (FL) is one of the basic biometric parameters used to assess fetal size.  Femur length together with biparietal diameter, head circumference, and abdominal circumference are computed to produce an estimate of fetal weight. In the second trimester this may be extrapolated to an estimate of gestational age and an estimated due date (EDD).

Ultrasound - obstetric
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Article information

rID: 26433
System: Obstetrics
Section: Approach
Tag: stub
Synonyms or Alternate Spellings:
  • femoral lenth
  • Femur length (FL)
  • femur diaphysis length

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Cases and figures

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    Case 1: normal FL
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