Cephalohematoma (CH) is a collection of blood between a baby’s scalp and the skull. Damaged blood vessels release the blood, and the blood pools into a mass under the skin of the scalp. The blood vessels are often damaged during labor and delivery.

Between 1 and 2 percent of all babies born will develop CH during or after birth, so it’s not a rare condition. It’s also not dangerous. The blood is sitting on top of the skull, not under the skull. That means the brain isn’t affected.

The most obvious CH symptom will be a soft, unusual bulge on the back of a baby’s skull. You likely won’t see a cut or bruise on the surface of the skin over the bulge.

Over the course of a few weeks, the bulge may feel harder as the blood calcifies. After a few weeks, the blood will start to disappear, and the bulge will shrink. Sometimes, however, the center of the bulge disappears before the edges. That may give the spot a crater-like feel.

Beyond this bulge, infants with CH may not display any obvious symptoms or behavioral differences. Instead, the symptoms may be more internal. These could include:

To diagnose CH, your doctor will perform a full-body physical on your infant. Often, the appearance of the bulge alone is enough to make a diagnosis.

For added precaution, your doctor may request additional tests, including:

If these imaging tests don’t reveal additional problems, your doctor will treat the area as CH. Both you and your doctor, however, should monitor for changing symptoms or signs of other problems with your baby.

CH is a minor injury that occurs most often during labor and delivery. For example, if an infant’s head is larger than their mother’s pelvic area, CH is more likely. An infant could hit their head against the mother’s pelvis during labor and rupture the delicate blood vessels.

Birth-assisting devices, such as forceps or a vacuum, also make these injuries more likely. Women who have a difficult or prolonged labor may need these devices, and the lengthy labor time may increase an infant’s risk for CH.

All infants could develop CH, but certain factors increase the baby’s risk for the injury. Women who have a longer labor or a complicated delivery are more likely to have a baby with CH. A lengthy labor also increases the potential need for birth-assisting devices. These devices make the injury more likely.

These risk factors can increase a woman’s labor time or make a complicated delivery more likely:

  • A large baby may have a difficult time moving through the birth canal, which slows down delivery.
  • The birth canal is too small for the infant.
  • Weak uterine contractions don’t push the infant into the birth canal.
  • The infant isn’t in a head-down, back-facing position. An abnormal position may make delivery longer and more complicated.
  • You’re carrying multiples.

Certain medications, especially pain medicines, also may weaken contractions and slow labor.

Read more: Birth canal issues »

In almost all cases, an infant won’t need treatment for CH. That’s because most of these injuries will heal on their own. You can expect the bump to go away in several weeks to a few months. Some injuries may take up to three months to heal completely.

In rare cases, your doctor may decide to drain the pooled blood. This isn’t always necessary, and it increases the infant’s risk of infection and an abscess.

Any complications of CH are temporary and often disappear as the bulge does. Most babies will have no long-term complications because of CH, and you shouldn’t expect to see any type of developmental delays as a result of the injury.

CH increases your infant’s risk for anemia and jaundice.

If your baby develops anemia as a result of CH, a blood transfusion may be necessary. A buildup of blood, such as CH, increases your baby’s risk for a low red blood cell count. A transfusion boosts the red blood cell number and likely eases any symptoms of anemia.

Jaundice is the result of excess bilirubin in the blood. Bilirubin is a yellow pigment found in red blood cells. As the blood from CH breaks down and gets reabsorbed, levels of bilirubin in the baby’s blood go up. If these levels measure higher than normal, your baby may develop jaundice. The most common symptom is a yellowish discoloration of the skin and eyes. The most common treatment for jaundice is phototherapy, or light therapy. Special lights break down the extra bilirubin, and it’s removed from the baby’s body in their urine and stool.

Your baby likely won’t need to remain in the hospital if they develop CH. Your baby’s doctor will ask you to monitor the accumulation and alert them to new symptoms if they occur before your baby’s next checkup.

If a new bulge appears or if your baby develops additional symptoms, seek immediate attention from your infant’s doctor. Likewise, if your baby’s skin starts showing a yellow tint, call the doctor. The yellow skin is a symptom of jaundice, and your doctor may prescribe phototherapy to help the baby’s body break down and remove excess bilirubin.

Aside from the minor complications, recovery from CH requires monitoring but little action. The outlook for a baby with CH is a positive one. CH doesn’t impact your child’s brain development and isn’t dangerous. Though it may be scary to feel and see one of these injuries on your infant’s head, rest assured it will go away with no lasting impact.