An umbilical hernia presents as a bulge at the site of the umbilicus, and in the pediatrician’s office, it is a common finding during routine well-baby visits for the first few months of life. New parents who are not very familiar with this anomaly might verbalize great concerns during these visits because they tend to become very worried when they see the bulge in their infant’s belly button. On the one hand, parents might be concerned with the idea that their child will suffer serious complications from an umbilical hernia, and they wonder if there are be any measures that they should take to avoid complications. On the other hand, they often are concerned about the cosmetic aspect of a hernia, and would like to know if their child will have this defect for the rest of his or her life. As a pediatrician, it is important to understand how to answer these questions and when it is time to refer the patient for surgical evaluation. Here we will discuss the background and general management of pediatric umbilical hernias.
There are three causes of an umbilical hernia:
Pediatric umbilical hernias are very common in children, with 15% to 23% of newborns affected in the United States. The defect is seen more often in certain ethnic groups. They are very common in African-American infants as well as in Hispanic infants, compared to whites, for reasons not precisely understood. This abdominal wall defect is also more commonly seen in low-birth-weight babies, but there has been no description of increased frequency in either of the genders.
It is important to know the embryologic processes involved in the formation of the umbilicus to understand more about umbilical hernias. In utero, the midgut initially develops extra-abdominally, until during the second trimester, when it will return to the fetal abdominal cavity. Once the midgut is back in the abdominal cavity, fascia forms to ensure the midgut remains in place. In case of weak fascia or failure to fully form the fascia, abdominal weakness may occur, which may predispose the newborn to an umbilical hernia. When the midgut fails to return intra-abdominally during the second trimester, and the newborn is born with the gut bulging out of the umbilicus, surrounded by a sac, this is not considered an umbilical hernia, but an omphalocele (one of the differential diagnoses for umbilical hernias). An omphalocele requires medical attention immediately after birth and surgical correction as soon as possible to prevent further damage to the protruding organs.
Additionally, for the umbilical vessels to pass to the umbilical cord, there is an opening in the umbilicus, a reason for which all newborns are born with a small umbilical defect. Since there is no function for the umbilical cord after birth, the umbilical ring usually closes in a matter of days to weeks. When the closure of the umbilical ring does not occur, it is considered an umbilical hernia, shown as a bulging through the umbilicus.
Of the hernias that appear before 6 months of age, the majority resolve by 1 year of age. Larger umbilical hernias may take longer, but most will be closed by 5 to 6 years of age. It is important to know what the risk of complications is when waiting for the defect to close spontaneously, to determine if and when the surgical repair would be needed.
Most studies looking into the complications of umbilical hernias have a significant selection bias because they only take into account patients that have undergone a surgical correction, leaving out a large proportion of patients with umbilical hernias who have never had any complication. The consensus remains that the risk of complications of a unrepaired umbilical hernia is very low.
During a well-child care visit, the history given by parents might include a swelling of the belly button, which increases when the baby is crying, coughing, or straining. During a physical examination, it is important to distinguish an umbilical hernia from an omphalocele. The pediatrician should determine the size of the abdominal wall defect and determine if a hernia is reducible, without having signs of incarceration or strangulation. An “elephant’s trunk” appearance (a crescent-shaped defect above an umbilical hernia) may indicate a component above the umbilicus and warrants surgical evaluation since these usually do not close spontaneously.
In the majority of cases, there are no medical sequelae to umbilical hernias. No tests are recommended, a thorough physical exam is sufficient to make the diagnosis and to discuss the common course of the condition with concerned parents. Although pediatric umbilical hernias are a common entity in healthy infants, they are also associated with some specific conditions, which the pediatrician should keep in mind when evaluating a patient. Pediatric umbilical hernias are seen more often in common autosomal trisomies (e.g., Trisomy 21 and 18), metabolic disorders (e.g., hypothyroidism, mucopolysaccharidoses) and some dysmorphic syndromes (e.g., Beckwith-Wiedemann syndrome, Marfan syndrome). For this reason, it is important to distinguish healthy patients with an innocent finding of an isolated umbilical hernia, from patients with an umbilical hernia and other syndromic features, for example, macroglossia or hypotonia, the latter group warranting further evaluation.
There are no strict guidelines as to the management of pediatric umbilical hernias, especially as to when to repair an asymptomatic umbilical hernia. Some textbooks recommend that surgery might be indicated in the following cases:
Cultural sensitivity and knowledge of how certain groups traditionally manage umbilical hernias allow practitioners to discuss the issue in a non-argumentative manner while respecting the family’s traditions and facilitating the education of parents about any misconceptions they might have. Some parents, for example, believe that placing a coin on the hernia will help to reduce it, but physicians should educate the parents about the ineffectiveness of that practice and the risk of dermatologic irritation and infection. It would be a good practice to ask parents what their thoughts are about an umbilical hernia and what they are concerned about, to be able to address those concerns individually.
While umbilical strapping has been suggested in the past as the treatment for umbilical hernias and this is a common practice in certain ethnic groups, this is not part of the routine treatment. The management for umbilical hernias is watchful waiting, together with educating the parents of the natural course of the condition: most hernias resolve in the first few years of life. Strapping might lead to some skin irritation when adhesives are used. Above all, do no harm.