Structural and functional early human development assessed by three-dimensional and four-dimensional sonography.

Objective: To summarize the role of three-dimensional and four-dimensional ultrasound in the assessment of early human development.

Design: Review of literature.

Setting: Ultrasound research center and obstetrics and gynecology department in a tertiary care facility.

Result(s): The introduction of high-frequency transvaginal tranducers has resulted in remarkable progress in ultrasonographic visualization of early embryos and fetuses and the development of sonoembryology. Furthermore, recent introduction of three-dimensional and four-dimensional ultrasounds combined with the transvaginal approach has produced more objective and accurate information on embryonal and early fetal development. For the first time parallel analyses of structural and functional parameters in the first 12 weeks of gestation become possible.

Conclusion(s): The anatomy and physiology of placental and embryonic development is a field where medicine exerts its greatest impact on early pregnancy at present time, and it opens fascinating aspects of embryonic differentiation. Clinical assessment of those stages of growth rely heavily on three-dimensional and four-dimensional sonography, one of the most promising forms of noninvasive diagnostics today and embryological phenomenon, once matters for textbooks are now routinely recorded with outstanding clarity.