Alternate Names : Molding of the Newborn's Head, Newborn Cranial Deformation

Information

Abnormal head shape resulting from pressure on the head during a vertex (head first) delivery.

Compared to an adult, a newborn's head is large in proportion to the rest of the body, usually about 1/4 of the body surface area. The bones of the skull are soft and pliable with gaps between the plates of bone. These gaps close as the bones grow and the brain reaches its full growth. The spaces between the bony plates of the skull are called cranial sutures. There are two gaps that are particularly large, the anterior and posterior fontanelles. These are the soft spots you can feel when feeling the top of your baby's head.

During a vertex birth (head first), pressure on the head caused by the tight birth canal may "mold" the head into an oblong shape. Depending on the amount and duration of pressure, the skull bones may even overlap. In addition, fluid collecting in the scalp (caput succedaneum) or blood beneath the scalp (cephalohematoma) may further distort the shape and appearance of the head. This is typically a source of much concern for new parents, but it is a common occurrence that usually disappears after a few days.

If your baby is born breech or with delivery by cesarean section, the head is usually round and otherwise well shaped.

Extreme abnormalities in head size typically are not related to molding and may be caused by:

• microcephaly (abnormally small head size)
• hydrocephalus ("water on the brain")
• craniostenosis (premature closure of the cranial sutures)
• plagiocephaly (asymmetry resulting from cranial pressure while in the womb)

Other conditions that may result in an abnormally shaped head include:

• cephalohematoma
• caput succedaneum
• birth defects