Please note that all guidance is currently under review and some may be out of date. We recommend that you also refer to more contemporaneous evidence in the interim.
An inguinal hernia is a peritoneal pouch that extends through the inguinal canal, sometimes as far as the scrotum. The bowel can also pass into it.
An inguinal hernia usually presents as an inguinal swelling that is often intermittent. Therefore it may not be noticed until the baby cries or strains.
All inguinal hernias require prompt surgical referral once diagnosed because the small bowel can easily become trapped in the hernia compromising the bowel's blood supply and causing bowel obstruction (strangulation).
Symptoms of strangulation
Symptoms of strangulation include:
- inability to squeeze the hernia back (irreducible)
- excessive crying
- vomiting, abdominal distension and constipation (later).
Cause of inguinal hernia
The testis descends into the scrotum in the 28th week in utero through a diverticulum of the peritoneum, the processus vaginalis.
Failure of obliteration of the processus vaginalis leads to inguinal hernias, hydroceles and encysted hydroceles of the cord.
Inguinal hernias are more common in premature babies.
They can occasionally occur in females (and are more common in preterm than term females).
Hydrocele is common. It is a painless fluid filled sack around the testis present from birth. It may not be possible to feel the testis separate from the hydrocele if the hydrocele is tense. Points to note about diagnosis of a hydrocele:
- Parents should be reassured that the fluid does not harm the testis and that it will usually resolve within a year.
- No follow-up is required if both testes are felt and a hernia is not suspected.
- A hydrocele must have all three of the following features otherwise a hernia should be suspected:
- a narrow spermatic cord felt above the swelling
- it transilluminates
- it does not empty on squeezing.
Undescended testis or retractile testis
The undescended testicle (cryptorchidism) is one that has never entered the scrotum.
A retractile testicle is one that may move back and forth from scrotum to groin.
Encysted hydrocele of the cord
An encysted hydrocele of the cord:
- is a discrete painless swelling within the spermatic cord, above the testis and below the external inguinal ring
- usually resolves spontaneously.
Points to note about management of hernia:
- A reducible inguinal hernia requires an early surgical consult and will usually be repaired on the next convenient surgical list.
- An irreducible or strangulated hernia requires urgent surgical referral.
- Premature infants should have their hernia repair prior to discharge.
Postoperative apnoea is less common after 42 corrected weeks of gestation.
- Auckland District Health Board newborn services clinical guideline
- Royal Children's Hospital - Inguinal hernia
- Hutson, J.M., O'Brien, M., Woodward, A.A., and Beasley, S.W. (editors). Jones' Clinical Paediatric Surgery. 6th edition. Blackwell Publishing. 2008.
- Thomson, K., Tey, D., and Marks, M., Paediatric Handbook. 8th edition. Wiley-Blackwell Publishing. 2009.
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First published: May 2015
Last web update: June 2016
Review by: June 2019
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Page last updated: 17 Feb 2021