Two-dimensional and three-dimensional Doppler assessment of fetal growth restriction with different severity and onset

Objectives: To investigate the role of three-dimensional (3D) power Doppler ultrasonography in the assessment of fetal growth-restriction (FGR) with various degrees of severity and onset, and compare the results with the analysis of two-dimensional (2D) Doppler. Study design: Vascular indices extracted from 3D Doppler measurements of the placenta were compared with indices of flow-velocity waveforms extracted from 2D Doppler measurements of the major sites of the fetal circulation between FGR (study group) and uncomplicated pregnancies (control group) from 25 to 38weeks' gestation. Results: Three-dimensional indices were significantly lower in pregnancies complicated by FGR compared with uncomplicated pregnancies. When measured in placental periphery, vascularization index was 9.4±9.6 in FGR pregnancies compared with 16±14.7, P=0.04. Flow index was 33.9±6.9 compared with 38.7±4.9, P=0.03 and the vascularization-flow index was 3.8±4.3 compared with 6.5±6, respectively, P=0.03. Among the conventional 2D indices, umbilical artery and middle cerebral artery pulsatility indices were not significantly different between the FGR and control groups. Higher rate of maternal or fetal compartment vascular lesions were detected in the FGR group. Conclusions: Three-dimensional Doppler was found to be more strongly associated with placental vascular compromise than conventional 2D Doppler, regardless of severity and onset of fetal growth restriction.