What is it?
Before a baby is born, the testicles and ovaries begin life high in the back of the belly. A band-like cord forms, called the gubernaculum. This attaches to the testicle or ovary on one end, and to the inside of the scrotum or labia on the other end. Slowly, the gubernaculums pulls and guides the testicles down through a tube called the inguinal canal and out into the scrotum (the descent of the testicles). The ovaries also descend, into the pelvis, but they do not exit the abdomen. Then, the slippery inguinal canal closes permanently – the walls fuse together – in the few weeks surrounding birth.

If the canal does not close, the child has an inguinal hernia. The open canal allows some of the intestines to slip through from time to time and create a bulge in the groin.

Who gets it?
Babies who are born prematurely are far more likely to develop hernias than those who are born at term. Boys are also far more likely to have hernias than girls.

Hernias can also run in families. In addition, they are associated with a number of other conditions including undescended testicles, hypospadius, inconspicuous penis, congenital hip dislocation, and cystic fibrosis.

In most children with inguinal hernias, the intestines first squeeze through to create a bulge sometime within the first year (usually the first six months). Sometimes, however, the opening is so small that the bulge does not occur for years. It may even first occur when straining as an adult. In some, a bulge never occurs.

What are the symptoms?
Parents usually notice a lump or bulge in the groin, scrotum, or labia. It may be present only during crying or straining, and disappear when the child is relaxed or asleep. Most of the time this does not cause discomfort. The bulge is noticed during a regular bath time or diaper change.

Occasionally, some of the intestine will get trapped (incarcerated) in the hernia. This causes acute swelling and pain, and must be treated immediately. The child is fussy and may cry without being consolable. There may also be signs of intestinal obstruction, such as vomiting, constipation, and abdominal distension. Sometimes the child is thought to have appendicitis, if the bulge has not yet been discovered. When the incarcerated hernia is identified, usually the intestines can be maneuvered back into the abdomen. Surgery is scheduled for the near future.

If the blood supply to the incarcerated intestine is cut off, the child has a strangulated hernia. The bulge is often red and extremely tender. In addition to the symptoms of incarceration, the child may have a fever and a racing heart rate. This is very uncommon in children, but requires emergency surgery.

Is it contagious?
No

How long does it last?
An inguinal hernia lasts until it is corrected surgically.

How is it diagnosed?
The diagnosis is often based on the history and physical exam. Sometimes a hernia can be difficult to distinguish from a hydrocele. If the size of the bulge varies significantly from time to time, it is a hernia. If not, time will often clarify the issue (see “hydrocele”).

When girls have hernias, they should be checked to be sure that they have a uterus. Most do, but in rare cases the uterus is absent, because the child is a boy with female external genitalia.

How is it treated?
Inguinal hernias do not go away without treatment. Closing the inguinal canal requires a simple, safe operation. It is usually scheduled as an outpatient procedure soon after the diagnosis (to prevent a possible incarceration). When closed before incarceration, the risks from the hernia itself, or from the surgery or anesthesia are extremely low.

Incarcerated hernias require emergency treatment.

In general, the results are excellent. The risk of complications is much higher (about 5 percent) if the hernia has become incarcerated before repair. The major complication is damage to the testicles from the incarceration.

How can it be prevented?
Inguinal hernias can be difficult to prevent. Good prenatal care can decrease the risk of prematurity, which can decrease the risk of hernias.

Related A-to-Z Information:
Anorectal Malformations (Imperforate anus), Appendicitis, Colic, Congenital Hip Dislocation, Cystic Fibrosis, Dehydration, Hydrocele, Hypospadius, Inconspicuous Penis, Intussusception, Labial Adhesions, Undescended Testicle (Cryptorchidism), Vomiting

Alan Greene MD FAAP