Three-dimensional first trimester fetal volumetry: Comparison with crown rump length

Background: Ultrasonographic volumetry measurements of human fetus have become possible using three-dimensional ultrasound systems. Objective: To evaluate the weekly increase of fetal volume during the first trimester of normal pregnancies compared to the crown rump length and creating a first trimester fetal volume nomogram. Methods: Crown rump length and three-dimensional ultrasonographic volumetry measurements performed on 72 first trimester fetuses using virtual organ computer aided analysis (VOCAL). Results: A significant direct correlation (r=0.939) was found between the calculated fetal volumes and crown rump lengths. A 6-12 weeks gestation fetal volume nomogram was proposed. Conclusion: Fetal volume database in the first trimester may serve as a reference table for diagnosis of early pregnancy failure.