baby

Google + wikipedia is the key. A cephalic presentation or head presentation or head-first presentation is a situation at childbirth where the fetus is in a longitudinal lie and the head enters the pelvis first; the most common form of cephalic presentation is the vertex presentation where the occiput is the leading part (the part that first enters the birth canal).[1] All other presentations are abnormal (malpresentations) which are either more difficult to deliver or not deliverable by natural means.