Three-dimensional sonography for assessment of morphology and vascularization of the fetus and placenta.

Objective: To analyze the potential of three-dimensional power Doppler sonography in morphologic and functional assessment of the fetus and placenta.

Methods: Review of the recent literature on three-dimensional sonography in early pregnancy and in the second and third trimester.

Results: Three-dimensional sonography plays an important role in obstetrics predominantly for assessing fetal anatomy. Multiplanar images and rotation of the object allow systematic review of anatomic structures, such as limb buds, cerebral cavities, cord insertion, stomach, and bladder. Using this modality, volumes of the gestational sac, yolk sac, and fetal organs can be obtained easily. Three-dimensional power Doppler sonography has the potential to study the intervillous and placental circulation and evaluate the development of the embryonic and fetal cardiovascular system.

Conclusions: Three-dimensional ultrasound imaging complements pathologic and histologic evaluation of the developing embryo, giving rise to the new term "three-dimensional sonoembryology." It is evident that three-dimensional ultrasonography improves the visualization of the normal and abnormal fetal anatomy giving a realistic impression of the extent of the defects. These data are useful not only for obstetricians but also for pediatricians and pediatric surgeons.