OB Dating Atlas - Week 17 - Femur Length
Caption
A 34-year-old G6P5 with an LMP of “a few months ago” presents for vaginal spotting. She had a positive UPT 5 days ago. FL measures 2.42cm, consistent with a 17w2d IUP. General Rules: Measure diaphyseal length only (excluding epiphysis) with the length of the bone perpendicular to the ultrasound beam A simple measure to get in a critically ill medical or surgical patient to determine if the fetus is viable outside of the uterus [4] Accuracy3: ± 7 - 17 d