Efficacy of fetal thigh volumetry in predicting birth weight using the virtual organ computer-aided analysis (VOCAL) technique.

OBJECTIVES The present study was conducted to compare the accuracy of formulas used to calculate fetal thigh volume (FTV) using the virtual organ computer-aided analysis (VOCAL) technique with two-dimensional (2D) in formulas predicting birth weight. MATERIALS AND METHODS This was a prospective, cross-sectional study of 84 pregnant women with 72 hours of delivery evaluated at a university hospital between May, 2008 and April, 2010. After 2D ultrasounds (US) measurement, 3DUS was also used to determine FTV with estimates computed using the VOCAL program. RESULTS The correlation between fetal weight predicted by the 3D equation of FTV and the actual birth weight was significant. While FTV and the Hadlock II equation exhibited a low sensitivity for detection of low-birth-weight infants, FTV was a more sensitive method of detecting high-birth-weight infants than the Hadlock II equation. CONCLUSIONS It is clear that using 3DUS-VOCAL to measure FTV provides more accurate estimation of fetal birth weight.