The Facts on Caput Succedaneum, From Causes to Treatment

Soon-to-be parents shouldn't expect their new baby to emerge from the womb with a perfectly smooth, round head. Infants come out with misshapen, elongated, and even swollen noggins all the time, and it's completely normal.

One of the most common birth conditions affecting babies is caput succedaneum, defined as swelling due to fluid collection between the skin and the layer of connective tissue above the skull. It can appear like a puffy bump or "cap" on the infant's head.

A baby's head is typically disproportionately large for their body, and the plates of the skull aren't fused together yet. "That's by design so they can get through the birth canal," says Nicole Glynn, M.D., a pediatrician with Getzwell Pediatrics in San Francisco and a member of the American Academy of Pediatrics (AAP).

Caput Succedaneum Causes and Treatment

During vaginal delivery, the flexible plates that form an infant's skull contract and overlap to help the baby squeeze through the cervical opening and into the birth canal. Pressure from the parent's dilated cervix or vaginal walls can cause the baby's head to swell. Using forceps or suctioning is an additional risk factor for caput succedaneum and can make the condition more pronounced.

According to the AAP, this type of swelling can happen before labor if the fetus "drops" well before birth, making head-first contact with the parent's pelvis. Likewise, the parent's water breaking early can have a similar effect since the "water" (or amniotic fluid) is what normally cushions an infant's head against their parent's pelvic bones. For both of these reasons, even babies born via C-section can experience caput succedaneum, says Dr. Glynn.

There's no treatment for caput succedaneum, and it's not dangerous—it typically clears up on its own. And while it may cause your baby slight discomfort, it does not cause severe pain, nor does it require any special care by parents. "When a baby has caput succedaneum, it's usually resolving by the time I see them for their first visit a few days after they're born," says Dr. Glynn.

Caput Succedaneum vs. Cephalohematoma

Caput succedaneum, by definition, is not a hematoma or localized bleeding, but it can look a lot like cephalohematoma. This is another infant condition related to birth injuries, but unlike caput, it's characterized by internally broken capillaries and the pooling of blood deep under the skin, closer to the skull. Cephalohematoma usually heals on its own, though it may take a few months to resolve completely.

One way to tell the difference between the two conditions is to draw an imaginary line from the center of your baby's forehead to the nape of their neck. Swelling that's caused by caput succedaneum will cross this "midline" between the right and left brain. Swelling that's attributed to cephalohematoma does not cross the midline, says Dr. Glynn, but will be contained to one side of it.

What If Baby's Caput Succedaneum Is Not Going Away?

"It is very rare, but both caput succedaneum and cephalohematoma can become infected," says Dr. Glynn. Cephalohematoma, in particular, can "calcify and eventually ossify, or turn to bone," she says, and sometimes, surgery is needed to remove an "ossified cephalohematoma."

Dr. Glynn recommends contacting your doctor if you notice increasing redness or lesions growing in size on your baby's scalp or if your little one is lethargic, extremely irritable, or running a fever, which is "never normal in a baby," she says.

The Bottom Line

Caput succedaneum sometimes referred to as "newborn conehead," is a common condition that causes temporary swelling of a newborn's head and typically resolves itself within a few days to a few weeks after birth.

If the swelling does not appear to be going down or new symptoms appear, such as jaundice (changes in the baby's skin or eye coloring), call your doctor right away. In some cases, newborns will experience hair loss at the site of swelling, but that is harmless, and the hair will grow back.