An inguinal hernia in a child is not the same as one in an adult. In adults, watchful waiting is sometimes appropriate. In infants and young children, the risk of incarceration is considerably higher — around 12 per cent overall in infancy, higher still in premature babies — and strangulation of trapped bowel or ovary can occur within hours of incarceration. For this reason, surgical repair in paediatric practice is recommended promptly after diagnosis rather than delayed.
The hernia itself may be barely visible when the child is lying quietly, appearing only as an intermittent groin swelling when the child cries or strains. Parents who notice a swelling that appears and disappears in the groin or labia should have it assessed promptly.
Healthbooq (healthbooq.com) covers children's surgical conditions and health through the early years.
How an Inguinal Hernia Forms
During foetal development, the processus vaginalis — a finger-like extension of the peritoneum (abdominal lining) — descends into the scrotum in boys or toward the labia in girls. This channel normally closes before or shortly after birth. If it remains patent (open), it creates a pathway through which abdominal contents can protrude into the groin.
In boys, the hernia sac passes through the internal inguinal ring, along the inguinal canal, and may descend into the scrotum (an inguinoscrotal hernia). In girls, the hernia sac enters the inguinal canal and may contain the ovary and fallopian tube — a finding in approximately 15 to 20 per cent of girls operated on for inguinal hernia.
Inguinal hernias are far more common in boys (approximately 80 to 90 per cent of cases). They are also much more common on the right side (approximately 60 per cent) because the right processus vaginalis closes later in development. About 10 per cent are bilateral at presentation.
Who Is at Higher Risk
Prematurity is the biggest risk factor. The processus vaginalis is more likely to remain open in preterm infants, and the incarceration risk is higher. Among premature infants, inguinal hernia incidence reaches 30 per cent.
Other risk factors include a family history of inguinal hernia, connective tissue disorders, conditions causing increased intra-abdominal pressure (chronic cough, ventriculoperitoneal shunt), and undescended testes.
Presentation
The classic presentation is a parent noticing an intermittent swelling in the groin, labia, or scrotum that appears when the baby cries, strains, or stands, and disappears when the child is quiet or lying down. At rest the groin may look completely normal.
In infants, the swelling may be first noticed during a bath or nappy change. In older toddlers, it may appear with increased activity.
An incarcerated hernia presents differently: the swelling is firm, tender, and irreducible — it does not disappear with rest. The baby is often inconsolable and distressed. Vomiting may occur. If left untreated, this progresses to strangulation, where the blood supply to the trapped contents is cut off, leading to bowel ischaemia or ovarian infarction. This is a surgical emergency.
Assessment
A GP can often diagnose an inguinal hernia clinically by finding a palpable swelling in the inguinal canal or by seeing the hernia appear when the infant cries. Ultrasound is used when the diagnosis is uncertain, when a scrotal swelling needs to be distinguished from other causes (hydrocele, testicular torsion, lymph node), or when the ovary is suspected to be in the hernia sac.
Hydroceles (fluid around the testicle) are common in infant boys and are not hernias — they are soft, transilluminate (light passes through them), and the testicle is palpable below them. Most communicating hydroceles resolve by age two.
Surgical Treatment
Inguinal hernia repair (herniotomy) is the standard treatment for all children. In paediatric practice, the operation involves ligating and dividing the patent processus vaginalis at the internal inguinal ring — there is no mesh or any modification of the inguinal canal required, because the defect is the persistent channel, not a weakness in the muscle wall.
The operation is typically done as a day case. In infants under six months of age, general anaesthetic carries slightly higher risks, and repair is often done as soon as practically possible after diagnosis rather than waiting. Some centres offer regional or spinal anaesthesia for small infants.
For a contralateral (opposite side) hernia, the risk of the other side being positive is around 30 per cent, and some surgeons explore the other side laparoscopically at the same operation.
An incarcerated hernia that can be manually reduced is managed with gentle pressure (taxis) under sedation or analgesia, followed by repair within 24 to 48 hours once the swelling has settled. A hernia that cannot be reduced is a surgical emergency.
Key Takeaways
An inguinal hernia occurs when a loop of intestine (or, in girls, the ovary) protrudes through a weakness in the groin. It is the most common surgical condition in childhood, affecting approximately 1 to 5 per cent of all children and up to 30 per cent of premature infants. Unlike umbilical hernias, inguinal hernias in children do not resolve spontaneously and require surgical repair. The main risk is incarceration — the hernia becomes trapped and cannot be reduced — which can progress to strangulation, cutting off blood supply to the trapped bowel or ovary. Repair is typically recommended promptly after diagnosis.
