The physical changes that occur during gestation are often a source of curiosity, and the transformation of the navel is a frequently observed phenomenon. Many people notice their “innie” belly button becoming flat or even turning into a temporary “outie” as their pregnancy progresses. This visible shift in the navel’s appearance is a normal part of the body adapting to the growing fetus.
Why the Navel Changes Shape During Pregnancy
The primary reason for the navel’s change is the significant increase in internal pressure within the abdomen. As the fetus grows, the uterus expands upward and outward, pushing against the abdominal wall. This mounting pressure acts on the navel, which is a scar and generally a weaker point in the abdominal fascia.
The navel, or umbilicus, marks the site where the umbilical cord once attached, and the skin and tissue there are less structured than the surrounding muscle. When the abdomen stretches due to the expanding uterus, the skin becomes taut. Any inward indentation, like an “innie” navel, is forced to flatten out, which often leads to the temporary protrusion described as an “outie.”
The stretching is particularly noticeable because the connective tissue that runs vertically down the center of the abdomen, known as the linea alba, also stretches and thins. This mechanical pushing from the inside, combined with the stretching of the abdominal wall, causes the navel to protrude. The extent of this change varies widely between individuals, depending on factors like skin elasticity, the amount of surrounding fat tissue, and the position of the uterus.
When Does the Change Occur and Does It Reverse?
The navel usually begins to change shape in the late second or early third trimester of pregnancy. This timing corresponds with the point when the uterus has expanded significantly enough to rise out of the pelvic cavity and put direct pressure on the front of the abdomen. Many individuals first notice the change around 20 to 26 weeks of gestation.
The shift from an “innie” to an “outie” is generally gradual, though it may seem sudden as the pressure reaches a tipping point. Since the uterus is at its largest in the final trimester, the pressure is at its peak. This makes the final trimester the most likely time for the navel to fully protrude, which is a harmless physical effect of accommodating the growing baby.
The change is almost always temporary and reverses after delivery. Once the baby is born, the significant internal pressure is immediately relieved, and the uterus begins shrinking back to its pre-pregnancy size. Over the course of the next few months postpartum, the abdominal skin and muscles gradually retract and regain tone.
For most people, the navel will retreat and return to its original “innie” state. While the shape or appearance may be slightly altered due to the stretching, the navel typically settles back into its familiar contour within a few months after giving birth.
Navel Changes Versus Umbilical Hernia
A protruding navel during pregnancy is a common and normal event, distinct from an umbilical hernia. The normal “outie” is simply the skin of the navel being pushed outward by the pressure of the uterus. This protrusion should feel soft and is usually painless.
An umbilical hernia, in contrast, occurs when a small loop of the intestine or fatty tissue pushes through a weak spot or opening in the abdominal muscle wall near the navel. While hernias are not uncommon during pregnancy due to the increased strain, they involve a deeper structural issue.
The key difference lies in the symptoms: a hernia often presents as a soft lump near the navel that may be accompanied by a dull ache or increased pain when coughing, sneezing, or bending over. If the bulge becomes hard, tender, or causes severe pain, it may indicate a rare but more serious complication called a strangulated hernia, and immediate medical consultation is necessary.