An “outie” belly button, or a protruding navel, is a natural variation in the appearance of the umbilical scar. This difference is determined by how the tissue heals after birth, resulting in a navel that extends outward rather than tucking inward. The formation of an outie is an anatomical occurrence and is generally a benign condition.
The Anatomy of Umbilical Cord Separation
All belly buttons begin with the umbilical cord, which connects the fetus to the placenta during pregnancy. After birth, the cord is clamped and cut, leaving a small stump attached to the baby’s abdomen. The stump is designed to dry out and shrivel away naturally.
This remaining stump typically detaches within one to three weeks after delivery, revealing the newly formed navel underneath. The belly button is essentially a scar that forms where the cord was attached to the abdominal wall. The difference between an innie and an outie is determined by how the underlying skin and scar tissue forms during this healing process, not how the cord was cut.
Primary Factors That Create an Outie
The appearance of a protruding navel can be attributed to two main causes that are variations of normal development. The first relates to the nature of the scar itself. Sometimes, the scar tissue, known as granulation tissue, is slightly thicker or more prominent, which pushes the skin outward as it heals. This benign protrusion is a result of the body’s natural scarring process.
Umbilical Hernia
The most frequent reason for an outie is the presence of a minor umbilical hernia. This occurs when the opening in the abdominal muscles, through which the umbilical cord blood vessels passed, does not completely close after birth. A tiny piece of fatty tissue or a small loop of intestine can push through this opening, creating a soft bulge near the navel.
This bulge often becomes more noticeable when the baby cries, coughs, or strains, as increased internal pressure pushes the contents outward. Umbilical hernias are extremely common in infants, affecting up to one in five babies, and are usually painless and harmless. The vast majority of these minor hernias resolve completely on their own as the child’s abdominal muscles strengthen, typically closing up by the age of four or five years.
When an Outie Indicates a Medical Concern
While most protruding navels are normal, an outie caused by an umbilical hernia needs monitoring for signs of complication. Parents should seek medical attention if the bulge begins to grow rapidly or becomes firm to the touch. A normal umbilical hernia should be soft and easily reducible, meaning it can be gently pushed back in.
A serious complication occurs when the tissue that is protruding becomes trapped in the muscle opening, a condition known as incarceration. Signs of a trapped hernia include the area becoming tender or painful when touched, or if the skin over the bulge changes color, appearing dark, red, or purple. These color changes suggest that the blood supply has been cut off, which constitutes a surgical emergency.
Other worrying signs include persistent vomiting, significant distress, or an inability to pass gas or stool, which can indicate an obstruction. Surgical correction is rarely required unless the hernia is very large, does not close by school age, or shows signs of complication. For a typical, soft, and painless outie, a “watch and wait” approach is the standard medical recommendation.