EFW
Also written as: EFW — Estimated Fetal Weight
Estimated Fetal Weight - calculated measurement derived from ultrasound biometrics to assess fetal growth.
Full Definition
Estimated Fetal Weight (EFW) is a calculated parameter derived from multiple ultrasound biometric measurements, typically including biparietal diameter, head circumference, abdominal circumference, and femur length. Various formulae exist (Hadlock, Shepard, etc.) with accuracy varying by gestational age and fetal size. EFW is plotted against gestational age percentiles to identify growth abnormalities such as intrauterine growth restriction or macrosomia. While useful for clinical decision-making, EFW has inherent limitations with accuracy decreasing at extremes of fetal weight.
Usage
Usage note: Always specify formula used and percentile; note limitations in accuracy, especially at extremes.
In Context
- "The EFW was calculated at 3,200 grams (75th percentile) using the Hadlock formula." — Growth assessment ultrasound
- "Serial EFW measurements showed crossing percentiles, concerning for growth restriction." — High-risk pregnancy monitoring