Health & Medicine / Family Health

There is a little-known structure in the developing fetus called the urachus, which is a tube leading from the bladder to the umbilicus. The urachus is derived from a tubelike embryonic structure known as the allantois (Greek for “sausage”), which ­eventually forms the urethra, the urinary bladder, and part of the umbilical cord ­itself. By the time most babies are born, the urachus has collapsed down to a solid cord that connects the bladder with the back of the belly button and is useful only as a landmark for surgeons.

In rare cases, however, part or all of the urachus remains open after a baby is born. When the entire tube is open, the baby will leak small amounts of urine from his belly button. Partial closure can lead to a urachal sinus, a small pocket that remains at the upper end of the urachus and still maintains its connection to the cord. Sometimes that structure can become infected. A simple infected urachal sinus is treated with oral antibiotics and removed surgically after the infection clears. I suspected that was what I was dealing with.

When I described the condition to the pediatric surgeon, she agreed that a urachal sinus was likely and advised me to start antibiotics, order an ultrasound exam of the abdomen—which would detect any cystic dilation of the urachal tract—and schedule the baby for an appointment with her the following week. “And you know what to tell the parents to watch for,” she concluded.

“Right,” I said. “I remember seeing one case of omphalitis when I was a resident. It was ­awful.”

Omphalitis is the most frightening complication of an infected umbilicus or urachal sinus. Bacteria that colonize the cord can sometimes overwhelm the newborn’s immature immune system. Infection in a tiny area can then quickly spread to the loose, soft tissue around the cord and rapidly enter the baby’s bloodstream. The telltale sign is swelling and redness of the skin around the cord, which often leaks pus. Suddenly, the baby begins to look sick. Those infants, like my patient years ago, can die. The condition is extremely rare in the United States, but it has been a common cause of death in the past; it is still a problem in Africa and developing countries.

Fortunately, this child didn’t look sick, and I hadn’t seen any redness around her umbilicus. After talking with the surgeon, I went back and explained the plan to the parents, outlining what they should watch for. “Make sure to bring her in right away if she runs a fever, if she won’t nurse, or if she seems very lethargic or fussy. And ­especially if you see the skin around the belly button turning red,” I said.

The baby’s father pointed to his daughter’s small abdomen. “You mean like that?” he said. Around the umbilicus there was a faint tinge of red, which hadn’t been there just 30 minutes earlier.

This baby wasn’t going home.

I told the hospital’s admitting pediatrician that a newborn with early omphalitis ­needed immediate treatment with intravenous ­antibiotics, along with very careful ­monitoring. Fortunately, we had caught the infection in time, and the baby made a full recovery. I ­shudder to think what might have happened if the ­infection had gone unnoticed just a little bit longer.