The introduction of 3D/4D sonography with high frequency transvaginal transducer has resulted in remarkable progress in ultrasonographic visualization of early embryos and fetuses and development of new fields of 3D sonoembryology. With the proper use of this new diagnostic modality and with experienced examiner, both structural and functional development in the first trimester of gestation can be assessed more objectively and reliable. Indeed new technology moved embryology from postmortem studies to the in vivo environment. Furthermore, there are good reasons to believe that 3D/4D sonography moved prenatal diagnosis of fetal abnormalities from the second to the first trimester of pregnancy. We will try to illustrate it with the number of convincing slides.