EFW
Also written as: EFW — Estimated Fetal Weight
Ultrasound-derived calculation predicting fetal weight before delivery.
Full Definition
Estimated Fetal Weight - a calculated prediction of fetal weight based on ultrasound biometric measurements including biparietal diameter, head circumference, abdominal circumference, and femur length. Various formulas are used (Shepard, Hadlock, etc.) with accuracy typically within 15-20% of actual birth weight. EFW is crucial for delivery planning, particularly when macrosomia or growth restriction is suspected. Serial measurements help assess fetal growth velocity and guide timing of delivery in high-risk pregnancies.
Usage
Usage note: Typically written in all capitals. Include measurement method and gestational age for context.
In Context
- "The ultrasound showed an EFW of 4200 grams at 38 weeks gestation." — Prenatal ultrasound report
- "When documenting EFW, always include the percentile and formula used." — Ultrasound reporting guidelines