What’s the Difference Between an Umbilical Hernia and an Inguinal Hernia?

If you’ve been around babies enough, you may have heard of an infant having a hernia. And these words may have crossed your mind: “Hernias? I thought that was an old man problem?” But infants can get hernias, too, and in fact, there are a few kinds on hernias seen in infants. Let’s set the record straight on the different kinds of hernias, how to recognize them, and how to treat them.

Inguinal Hernias

When most people refer to a hernia, they mean an inguinal (ING-gwuh-nul) hernia, which is located in the groin. An inguinal hernia appears as a bulge or lump in the groin or in the scrotum. This occurs in about 5% of all children, but more commonly in boys.

A hernia occurs when the muscles of the lower abdominal wall get separated slightly and the intestines can squeeze through that opening. The bulge that is seen is actually the intestines coming through the opening and lying just under the skin.

Often, a parent can push on the bulge gently and the bulge will go away. This represents the intestines going backwards through the opening and back into the abdominal cavity. This is called a reducible hernia. Sometimes the hernia reduces or goes backward on its own, and in these cases, the bulge appears and disappears, seemingly at random.

Inguinal hernias are more common in premature babies, occuring in as many as 30% of premature and low birth weight newborns.1

In boys, a hernia can show up in the groin or in the scrotum. Sometimes, a hernia in the scrotum is confused with another problem called a communicating hydrocele. A hydrocele is a collection of fluid in the thin sheath around the testicle. It appears as a painless swelling in the scrotum. When the fluid is trapped in this sheath, it is a non-communicating hydrocele.

When the fluid can move freely from the abdominal cavity to the scrotum through an opening in the musculature, this is called a communicating hydrocele. Because the swelling in the scrotum comes and goes, sometimes parents and even physicians can mistake this for a hernia.

Hydroceles are common, and usually benign. Non-communicating hydroceles usually resolve on their own within the first year of life. However, communicating hydroceles can lead to a hernia and so often need to be corrected.

Hernias in infants are usually painless, but sometimes the intestine can get trapped in the small muscular opening. This is called an incarcerated hernia. This can lead to a severe constriction of the blood supply to the intestine (called a strangulated hernia), which can be very dangerous and even fatal. The bulge will often appear red or tender to touch, and the baby may have vomiting, pain, and crying. This is a surgical emergency, but is fortunately uncommon in infants.

If you suspect that your infant has a hernia, call your doctor. If it is reducible, then it is not an emergency, but should be evaluated at some point. If you cannot reduce the hernia or you suspect it is incarcerated, then call your doctor or go to the emergency room immediately.

Because of the risk of incarceration and strangulation, hernias are usually corrected surgically, and often laparoscopically. This involves closing the opening in the muscles (usually with a small patch) so that the hernia can’t recur. In most cases, both sides of the groin are explored and patched, even when the hernia is only on one side.1

The timing of the surgery is important. It is important to wait until the baby is a little older to tolerate the anesthesia and procedure better, but not to wait too long as the risk of incarceration goes up. For most premature babies, surgery is done before they leave the NICU. Performing the surgery at this time does not increase the risk of incarceration or surgical complications, but it may increase the risk of recurrence of the hernia.2

Umbilical Hernias

Like inguinal hernias, umbilical hernias are openings in the abdominal musculature through which the intestines will poke out and appear under the skin of the belly button or umbilicus. These are usually not subtle: the belly button may bulge out significantly. These are always reducible and often will rise and fall with increasing or decreasing abdominal pressure, such as when the baby coughs, cries, or strains to have a bowel movement.

Sometimes, parents think the umbilical hernia is simply an “outie,” the normal variant of the usually inverted belly button. But an “outie” is small, and consistent, whereas an umbilical hernia will rise and fall as described above.

These hernias are benign, and almost never become incarcerated or strangulated, and often resolve on their own over the first few years of life. However, they are cosmetically unappealing, so they are often surgically repaired if not resolved by the age of four years old. At least one study has shown that complications are more likely at ages younger than 4 for asymptomatic umbilical hernias.3

In more severe cases of umbilical hernias, the small intestine can poke out through the opening. This can very rarely cause ischemia and necrosis of the intestine and is potentially life-threatening. The bulge is often caused by fat or parts of the greater omentum.

Many parents or grandparents will try to put tape or a taped coin over the umbilical hernia, but this should be avoided as it can be harmful.4

References:

  1. Abdulhai S, Glenn IC, Ponsky TA. Inguinal hernia. Clin Periantol. 2017 Dec;44(4):865-877.
  2. Masoudian P, Sullivan KJ, Mohamed H, Nasr A. Optimal timing for inguinal hernia repair in premature infants: a systematic review and meta-analysis. J Pediatr Surg. 2018 nov 14.
  3. Zens TJ, et al. Age-dependent outcomes in asymptomatic umbilical hernia repair. Pediatr Surg Int. 2018 Nov 14.
  4. American Academy of Pediatrics. Umbilical Cord Care.
Ruben Rucoba
Dr. Rucoba has over 25 years of experience as a primary care pediatrician after completing medical school at the University of California, San Francisco. His clinical areas of expertise include caring for children with special health care needs and assisting families with international adoption. He has been a freelance medical writer since 2010, writing for health websites, continuing medical education providers, and various print outlets. He currently works at Wheaton Pediatrics in the suburbs of Chicago, where he lives with his wife and four daughters, including a set of twins.

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