The umbilical ring represents a fibrous opening within the abdominal wall that serves a specific purpose during fetal development. This structure encircles the umbilical cord, which acts as a conduit between the developing fetus and the placenta. Through this opening, the umbilical cord allows blood flow, delivering oxygen and nutrients to the fetus while carrying away waste products. Around the sixth week of embryonic development, the midgut, a section of the intestines, temporarily protrudes through this ring into the umbilical cord. This physiological herniation is a normal part of development, allowing for proper intestinal rotation and growth before the intestines return to the abdominal cavity by weeks ten to twelve of gestation.
The Umbilical Ring After Birth
Following birth, the umbilical cord is cut, leaving a stump on the baby’s abdomen. The umbilical ring then begins a natural process of contraction and closure. This opening in the abdominal muscles gradually constricts as fibrous tissue forms, eventually integrating into the solid abdominal wall. This physiological transformation typically occurs over the first few weeks to months of a baby’s life.
As the umbilical cord stump dries and detaches, usually within one to three weeks, the natural healing and closure of the umbilical ring create the navel, or belly button. This process involves the obliteration and fibrosis of the umbilical vessels, forming ligaments that contribute to the integrity of the abdominal wall. The successful closure of this ring is a routine part of infant development.
Complications from an Unclosed Ring
When the umbilical ring fails to close completely after birth, it can lead to a condition known as an umbilical hernia. This occurs when a portion of the abdominal lining, part of the intestine, or fluid from the abdomen protrudes through the remaining opening near the navel. Umbilical hernias commonly appear as a soft bulge at the navel.
The bulge associated with an umbilical hernia may become more noticeable when a baby cries, coughs, or strains, due to increased pressure within the abdomen. Conversely, it often becomes smaller or disappears when the baby is quiet or lying down. These hernias are a common occurrence in newborns and infants, affecting 10% to 20% of children, and are generally painless.
Managing an Umbilical Hernia
For the vast majority of umbilical hernias in infants, the standard medical approach involves “watchful waiting.” Most umbilical hernias, about 90%, resolve on their own as the child’s abdominal muscles strengthen, typically by 4 or 5 years. Surgical repair is usually delayed unless the hernia persists beyond this age or causes problems.
While waiting for a hernia to close, parents should be aware of specific warning signs that necessitate immediate medical attention. These include the bulge becoming hard, tender, discolored (red or darker than usual), or if the infant appears to be in pain, begins vomiting, or refuses to eat. Such symptoms could indicate a rare complication where the intestines become trapped or their blood supply is compromised. Avoid home remedies, such as taping a coin or other objects over the hernia, as these are not effective and can cause skin irritation or other problems.