Three-dimensional US assessment of hepatic volume, head circumference, and abdominal circumference in healthy and growth-restricted fetuses

PURPOSE: To establish reproducibility and normal values for fetal hepatic volume and its significance in identification of fetal growth restriction relative to head and upper abdominal circumferences according to a cross-sectional study design. MATERIALS AND METHODS: Pregnant women (n = 135) underwent ultrasonography. The coefficient of variation (CV) for hepatic volume scans obtained at 0 and 20 minutes and hepatic area tracings, performed twice for each scan, was determined (n = 20; range, 23-36 weeks). Normal data for hepatic volume and head and upper abdominal circumferences were obtained (n = 85; range, 20-36 weeks) and related to data from growth-restricted fetuses (birth weight < P5 centile; n = 24; range, 22-36 weeks). RESULTS: CV was 2.9% for volume scans and 1.6% for area tracings. In 85 uncomplicated cases, mean fetal hepatic volume (P50 centile) was 9.7 mL +/- 4.4 (SD) at 20 weeks and 96.4 mL +/- 8.2 at 36 weeks of gestation. In 24 growth-restricted fetuses, hepatic volume, head circumference, and upper abdominal circumference expressed as percentages of the normal P50 centile were 45%, 90%, and 82%, respectively. Mean difference in hepatic volume between fetal growth restriction and normal fetal development, as expressed with the z score, -4.32 +/- 1.4, was significantly different (P <.05) from that for head circumference, -3.04 +/- 1.3, but not from that for upper abdominal circumference, -4.7 +/- 1.2. Fetal hepatic measurement was obtained in 109 pregnancies. CONCLUSION: Acceptable reproducibility exists for hepatic volume determinations. In fetal growth restriction, reduction is more pronounced for hepatic volume than for head or upper abdominal circumference; hepatic volume is a better discriminator than head circumference but not upper abdominal circumference.