P21Fetal liver volume in normal and reduced fetal growth

Background To establish reproducibility and normal values for fetal liver volume and its significance in identifying fetal growth restriction relative to head (HC) and abdominal circumference (AC) according to a cross‐sectional study design. Method The measurements were obtained using a Voluson 530‐D for volume scanning. The coefficient of variation (CV) for liver volume scans (t 0 , t 20  min) and liver area tracings (t 0 : 2x; t 20 : 2x) was determined ( n : 20; 23–36 weeks). Normal charts for liver volume, HC, AC were constructed ( n : 60; 22–37 weeks) and related to data from growth‐restricted fetuses (birthweight < P5) ( n : 13; 23–36 weeks). Results CV is 2.9% for volume scans and 1.6% for area tracings. Mean liver volume (P50) ranges between 16.5 mL (± 5.9 (SD)) at 22 weeks and 101.8 mL (± 8.2 (SD)) at 37 weeks. In fetal growth restriction, liver volume, HC and AC expressed as percentage of the normal P50 is 45%, 91% and 83%, respectively. Mean difference in liver size between fetal growth restriction (FGR) and normal fetal development (Z score = Liver volume FGR – P50 normal /SD normal ) is −4.5 ± 1.6 (SD), which is significantly different ( P  < 0.05) from HC: − 3.2 ± 1.5 (SD), but not from AC: − 4.3 ± 1.3 (SD). Conclusion Acceptable reproducibility exists for liver volume determinations. Normal liver volume increases 6‐fold at 22–37 weeks. Fetal growth restriction: reduction is more pronounced for liver volume than HC and AC; liver volume is a better discriminator than HC, but not AC.