An umbilical hernia forms when the opening in a baby’s abdominal wall where the umbilical cord passed through doesn’t fully close after birth. This leaves a gap that allows tissue or part of the intestine to push outward, creating a soft bulge near the belly button. It’s one of the most common conditions in newborns, affecting 10 to 15 percent of all infants, and boys and girls are affected equally.
How the Abdominal Wall Normally Closes
During pregnancy, the umbilical cord connects to the baby through a natural opening in the abdominal muscles called the umbilical ring. After birth, a ring of dense connective tissue surrounding that opening is supposed to grow inward and seal the gap completely. This tissue contributes to the fibrous line running down the center of the abdomen and to the sheaths around the abdominal muscles on either side.
When this tissue proliferates normally, the ring contracts, the space fills in, and the belly button heals flat. An umbilical hernia happens when that proliferation is incomplete or absent at one or more points around the ring. The result is a weak spot, or a ring that stays partially open, giving abdominal contents a path to bulge outward beneath the skin.
Why Some Babies Are More Likely to Develop One
Premature and low birth weight babies face a higher risk because their abdominal wall tissue simply hasn’t had enough time to mature before birth. The connective tissue responsible for sealing the umbilical ring is still developing during the final weeks of pregnancy, so arriving early can leave that process unfinished.
African American infants also have a higher incidence, though the exact reason isn’t fully understood. Genetics likely play a role in how quickly and completely the connective tissue around the umbilical ring develops.
Certain genetic and metabolic conditions are associated with umbilical hernias as well. Babies with Down syndrome (trisomy 21), trisomy 13, or trisomy 18 develop them more frequently. The same is true for babies with Beckwith-Wiedemann syndrome, a condition that causes overgrowth, and congenital hypothyroidism, where low thyroid hormone levels from birth can slow tissue development. Children who need peritoneal dialysis, which increases pressure inside the abdomen, are also at greater risk.
What an Umbilical Hernia Looks and Feels Like
The hallmark sign is a soft, squishy bulge at or near the belly button. In many babies, the bulge is only visible when they cry, cough, or strain, because these actions increase pressure inside the abdomen and push tissue outward through the opening. When the baby is calm or lying down, the bulge often flattens or disappears entirely. You can usually press it gently back in, and this doesn’t cause pain.
The size varies. Some hernias are barely noticeable, while others can be the size of a golf ball or larger when the baby is upset. Size alone doesn’t determine severity. What matters more is whether the hernia can be pushed back in and whether it causes any symptoms beyond the visible bulge.
The Role of Crying and Straining
Parents sometimes worry that crying is causing or worsening the hernia. Crying doesn’t create the hernia. The gap in the abdominal wall is already there. What crying does is temporarily increase pressure inside the belly, making the bulge more prominent. The same thing happens with coughing, straining during a bowel movement, or any activity that tenses the abdominal muscles. Once the pressure drops, the bulge recedes. This cycle of appearing and disappearing is completely normal and doesn’t mean the hernia is getting worse.
Most Close on Their Own
The good news is that the vast majority of umbilical hernias resolve without any treatment. The connective tissue around the umbilical ring continues to develop after birth, and for most babies, it eventually finishes the job. Most hernias, regardless of size, close by age 3, and those still open at that point often close by age 5.
Size does influence the timeline. Small hernias (1 centimeter or less across) have about a 90 percent rate of spontaneous closure within five years. Larger hernias (more than 1 centimeter) close on their own about 80 percent of the time in the same window. Even a large hernia has a strong chance of resolving, so patience is usually the right approach for the first several years.
When Surgery Becomes Necessary
Surgical repair is straightforward and common when it’s needed, but it’s reserved for specific situations. The American College of Surgeons recommends repair if the hernia hasn’t closed by age 5, if it becomes incarcerated (stuck in the outward position and unable to be pushed back in), if the blood supply to the trapped tissue is compromised, or if the defect is large enough to be bothersome. In 95 percent of cases where the hernia is under 1 centimeter, surgery is never needed.
The repair itself involves a small incision near the belly button, pushing the protruding tissue back into place, and stitching the opening in the muscle closed. Recovery is typically quick, and most children go home the same day.
Warning Signs That Need Immediate Attention
Complications from umbilical hernias are rare in babies, but they do happen. The most serious is strangulation, where tissue gets trapped in the opening and its blood supply is cut off. Signs to watch for include a bulge that won’t flatten when the baby is calm and can’t be gently pushed back in, vomiting, sudden severe fussiness or pain, and color changes in the skin around the bulge. The skin may first look paler than usual, then turn reddish or darker. If you notice any combination of these, it’s a medical emergency.
Why Taping or Strapping Doesn’t Work
A persistent home remedy involves taping a coin or flat object over the bulge to hold it in. This does not help the hernia close any faster. The issue is a gap in the muscle and connective tissue layer beneath the skin, and external pressure on top of the skin doesn’t influence that tissue’s growth. Worse, taping objects to a baby’s skin can trap bacteria underneath, leading to skin irritation or infection. The Mayo Clinic specifically advises against this practice.