Parental concern about a newborn’s umbilical cord stump is common, especially if the tissue appears strange or develops an unexpected smell. The stump is the small piece of tissue remaining after the umbilical cord is cut at birth. This remnant must dry up and fall off so the skin underneath can heal and form the navel. A slight odor or discharge during this natural process is often a normal part of the body’s way of separating this tissue.
The Normal Umbilical Cord Healing Process
The umbilical cord stump begins a process of natural detachment shortly after birth, typically falling off between one and three weeks of age. This process, called dry gangrene, involves the tissue shriveling and hardening as it loses moisture. The color of the stump changes during this time, moving from a yellowish-green to a dark brown or black.
This drying is necessary for the stump to separate from the body and is not painful for the infant. The stump may ooze a clear or slightly blood-tinged, sticky fluid as it prepares to detach. A mild, musty odor can sometimes accompany the drying and decaying tissue, which does not signal a problem on its own.
Primary Reasons for Umbilical Stump Odor
The odor parents notice stems from two main mechanisms: moisture-related decay or a bacterial infection. The mild, musty smell associated with dry gangrene is due to the natural decay of the dead tissue. This odor is localized and not overpowering.
The most common cause of a localized, mild odor is the trapping of moisture, urine, or lint around the base of the stump. When the stump remains wet, the environment becomes ideal for common skin bacteria to thrive, creating a slight smell without a full infection. Ensuring the area stays dry often resolves this type of mild odor.
A foul, strong, or fishy odor is a primary symptom of a serious bacterial infection called omphalitis. This infection involves the umbilical stump and the surrounding tissues. If the odor is intense and accompanied by a thick, yellowish or greenish discharge, it indicates that medical attention is needed.
Umbilical Granuloma
Another potential cause of discharge and mild odor is an umbilical granuloma, which can form after the stump falls off. This is a small, soft, pink or reddish mass of scar tissue that secretes a light-yellowish fluid. While not an infection itself, the persistent moisture can lead to a secondary, mild odor and may require simple in-office treatment if it does not resolve.
Identifying Signs of Cord Infection
A foul smell, particularly one described as fishy or purulent, is a symptom that confirms a severe infection, medically termed omphalitis. This condition is uncommon but requires immediate attention because it can spread quickly and lead to systemic issues like sepsis.
The odor is accompanied by visual and physical signs of inflammation around the navel. Parents should look for redness (erythema) or discoloration that spreads outward from the base of the cord onto the abdomen. Swelling and hardening of the skin around the stump are significant physical indicators.
A thick, cloudy, or pus-like yellowish or greenish discharge from the stump is a strong sign of infection, distinct from the clear fluid seen during normal healing. The infant may also exhibit systemic signs.
Systemic Signs of Infection
Systemic signs include:
- A fever of 100.4°F (38°C) or higher.
- Unusual lethargy.
- Increased irritability and pain when the area is touched.
These accompanying symptoms elevate the concern to a medical emergency.
Essential Care Practices and When to Call the Doctor
Proper care focuses on keeping the umbilical stump clean and dry to promote healing and prevent bacterial buildup. Parents should use a “dry cord care” approach, avoiding the application of alcohol or topical ointments unless instructed by a healthcare provider. The stump should be exposed to air as much as possible to help it dry out.
Only sponge baths should be given until the stump has completely fallen off and the navel is healed. If the stump becomes soiled with urine or feces, it should be gently cleaned with plain water and a soft cloth, then thoroughly patted dry. The top of the diaper should be folded down below the stump to prevent irritation and exposure to moisture.
Immediate medical attention is necessary if any signs of omphalitis are present, including a persistent, foul odor or thick, yellowish discharge. Urgent contact with a pediatrician is also warranted if:
- The skin around the navel shows spreading redness.
- The area becomes warm or swollen.
- The infant develops a fever.
- The infant is showing signs of lethargy or poor feeding.
If the stump has not detached after four weeks, a doctor should be consulted to rule out any underlying issues.