Newborn head molding is an abnormal head shape that results from pressure on the baby's head during childbirth.

The bones of a newborn baby's 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 size.

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 head-first delivery, pressure on the head caused by the narrow birth canal (vagina) may mold the head into an oblong shape. Depending on the amount and duration of pressure, the skull bones may even overlap.

Fluid may also collect in the baby's scalp (caput succedaneum) or blood may collect beneath the scalp (cephalohematoma). This may further distort the shape and appearance of the head. Fluid and blood collection in and around the scalp is a common occurrence during delivery and usually disappears after a few days.

If your baby is born breech (buttocks or feet first) or by cesarean section, the head is usually round and otherwise well shaped. Extreme abnormalities in head size are NOT related to molding. See:

• Craniosynostosis
• Macrocephaly (abnormally large head size)
• Microcephaly (abnormally small head size)