Lead
"The belly button is sticking out." "There's a soft lump in the groin." These observations are common at newborn checkups. Both conditions go by the name "hernia," but they are not the same illness and they are not managed the same way. One typically resolves on its own; the other usually requires surgery. Mixing up the two leads to either unnecessary anxiety or a missed sense of urgency.
Understanding the difference is the kind of knowledge that helps a parent sit calmly in the examination room.
Umbilical Hernia — Most "Outies" Close on Their Own
An umbilical hernia: a soft bulge at the belly button caused by incomplete closure of the abdominal muscles around the umbilical opening; common in newborns and usually closes on its own occurs when the umbilical ring — the opening in the abdominal wall through which the umbilical cord passes — does not close completely after birth. It is seen in 10–20% of newborns and is more common in premature and low-birthweight infants [1]. When the baby cries or strains, the navel protrudes visibly. The bulge is soft and can be easily pushed back into the abdomen.
Spontaneous resolution is the norm. For umbilical hernias smaller than 2 cm in diameter, more than 90% close by age two [2,3]. If a hernia persists at age five or its diameter exceeds 2 cm, surgical repair (umbilicoplasty) becomes a reasonable consideration [3].
The traditional practice of "coin taping" — pressing a coin over the navel with tape — and adhesive strapping in general have not been shown to improve the overall closure rate compared with observation alone in a recent meta-analysis, and skin complications have been reported in up to 26% of treated cases [6]. Most pediatric surgery departments do not recommend it. Watchful waiting is the default approach.
Incarceration — the bowel becoming trapped in the hernia and unable to return — is extremely rare with umbilical hernias [4]. If the bulge suddenly becomes firm and the baby cannot be consoled, that warrants a medical visit.
Inguinal Hernia — Why Surgery Is the Expected Treatment
An inguinal hernia occurs when the processus vaginalis — a channel of peritoneum in the groin — fails to close after birth. It affects 1–5% of all children and is far more common in boys (male-to-female ratio of 5–10:1) [1]. A soft lump appears in the groin when the baby cries or stands, and typically retreats when the baby is at rest.
Unlike umbilical hernias, inguinal hernias do not resolve spontaneously. Surgery is the standard treatment. More importantly, the risk of incarceration: trapping of tissue (such as bowel) inside a hernia, where it cannot be pushed back in; this can cut off blood supply and become a surgical emergency is significant: bowel — and occasionally, in girls, the ovary — can become trapped in the inguinal canal, cutting off blood supply. This is a surgical emergency. The incarceration rate in infants under 6 months has been reported at close to 30% [1], which is why a newly diagnosed inguinal hernia should not wait long before pediatric surgical evaluation.
The signs of incarceration are clear: the baby cries suddenly and inconsolably, and the lump in the groin becomes firm and does not reduce. Vomiting accompanying this picture increases urgency further.
Surgical repair (herniotomy) ligates the processus vaginalis through the groin; laparoscopic approaches are now common and have a good safety record in infants, with low rates of postoperative complications [5].
A Note for Boys — Check for Undescended Testicle at the Same Time
In boys with an inguinal hernia, there is a possibility of an associated undescended testicle (cryptorchidism): a condition where one or both testicles fail to move from the abdomen into the scrotum before birth; surgical correction is recommended if it persists past infancy — the testicle not having descended into the scrotum. Because undescended testicle carries long-term implications for fertility and cancer risk, the position of the testicle should be checked whenever an inguinal hernia is identified in a boy. The general clinical guidance is that if the testicle has not been confirmed in the scrotum by age one, referral to pediatric surgery or urology is appropriate.
Translating Evidence into Everyday Decisions
- Umbilical hernia ("outie"): Watchful waiting is the default if the hernia is small. There is no need to push it back manually or tape coins over it. Residual hernia at age five, or a large diameter, is the usual threshold for surgical consultation with a pediatrician or pediatric surgeon
- Inguinal hernia: Once diagnosed, confirm with your physician whether a referral to pediatric surgery is appropriate — in most cases, it will be. Incarceration (sudden firmness and inconsolable crying) is a surgical emergency
- Boys with inguinal hernia: Ask about the testicular position at the same visit
Recording the size of an umbilical hernia over time, or noting when and how often an inguinal hernia bulge appears, provides useful context for surgical decision-making and for any future visits.
Summary
Despite their superficial similarity, umbilical and inguinal hernias have different natural histories and different levels of urgency. Umbilical hernias resolve on their own in the great majority of cases — there is no reason to panic. Inguinal hernias carry a real incarceration risk and warrant timely surgical assessment. Knowing which is which prevents both unnecessary worry and a dangerous delay.
References
- Meier AH, Ricketts RR. Inguinal hernias and hydroceles. In: Mattei P, ed. Fundamentals of Pediatric Surgery. New York: Springer; 2011:647–652.
- Papagrigoriadis S, Browse DJ, Howard ER. Incarceration of umbilical hernias in children: a rare but important complication. Pediatr Surg Int. 1998;14(3):231–232. doi:10.1007/s003830050487. PMID: 9880742.
- Zendejas B, Zarroug AE, Ramirez T, Holley CT, Farley DR. Impact of childhood inguinal hernia repair in adulthood: 50 years of follow-up. J Am Coll Surg. 2010;211(6):762–768. doi:10.1016/j.jamcollsurg.2010.09.001. PMID: 21109162.
- Burd RS, Heffington SH, Teague JL. The optimal approach for management of metachronous hernias in children: a decision analysis. J Pediatr Surg. 2001;36(8):1166–1172. doi:10.1053/jpsu.2001.25757. PMID: 11479845.
- Osifo OD, Osagie TO, Udefiagbon EO. Outcome of herniotomy for inguinal hernia in the first year of life. Niger J Clin Pract. 2014;17(6):709–714. doi:10.4103/1119-3077.144377. PMID: 25385854.
- Sugimoto T, Tahara K, Uchida K, Yoshimoto K. Efficacy of adhesive strapping on umbilical hernia in children: a systematic review and meta-analysis of cohort studies. World J Pediatr Surg. 2023;6(4):e000633. doi:10.1136/wjps-2023-000633. PMID: 37860276.