The fetal pole is the baby. The top half becomes their head, the bottom half their spine and body.
The Fetal Pole is seen during pregnancy as a thickening on the margin of the yolk sac. The fetal pole is not really a fetus but is the embryo during a very early stage of pregnancy
. It looks very much like a small thickening on the side of the yolk sac contrary to most expectant mother's expectations. It gets its name from the fact that its puny size ensures no details can be seen on the ultrasound other than a tiny pole.