Figure 2. Ultrasound images of fetal development from embryonic day 10.5 to 14.5.

At E10.5, it is possible to identify the umbilical cord, placenta and eyes (a, b); a sagittal view of a dead embryo is shown in (c). At embryonic day 13.5, crown-rump length (d), placental length and placental thickness (e) can be measured; the distinction between the fetal thorax and abdomen is defined (f); eyes with lens (g) and vertebral column (h) are visible. At E14.5, the occipital-snout length measurement can be reported (i).