The disorder, called gastroschisis, is a congenital defect that was supposed to be uncommon, occurring nationally in just one or two births out of 10,000.

Dr. Matthew Laughon, a fellow in neonatology at UNC-Chapel Hill, was intrigued. He and a group of doctors thought maybe the teaching hospital was seeing more of the disorder because it tended to draw high-risk pregnancies.

But as they checked birth defect records across the state, they were shocked. The number of North Carolina babies born with gastroschisis had more than doubled in a short period of time, from 21 in 1997 to 54 in 2000.

An analysis of data from a consortium of 600 neonatal doctors nationwide showed that the prevalence of gastroschisis also was rising elsewhere. Laughon and his colleagues found that the consortium had seen a rise from 30 cases in 1997 to 149 in 2000.

"Once we started looking at the data more closely, it became pretty obvious we had a problem," Laughon said. "We don't know what causes the defect, number one, and we don't know why we would see an increase."

The UNC data offers researchers a starting point to explore those issues. If the cause of gastroschisis and its increasing prevalence could be discovered, a cure might soon follow.

"It may be something simple along the lines of spina bifida," Laughon said, referring to the neural tube defect that is curable, in 80 percent of cases, by adding folic acid to the mother's diet in the months before pregnancy.

Laughon said he suspects some unknown environmental exposure has triggered the increase -- perhaps a food additive, a common chemical, a drug.

Among birth defects, gastroschisis is one that can be treated successfully; it is fatal in only about one in 10 cases. But babies born with the anomaly require at least one surgery to fold their intestines back into their abdomens. In many cases, however, the baby's belly has not grown enough to handle the bulk, so the intestines are gradually returned over a period of several days.

Even then, the intestines don't work properly and take time to be coaxed into action. Most babies with gastroschisis spend one to three months in the hospital.

The Centers for Disease Control and Prevention estimated in 1992 that it cost $108,000 to treat a baby for the disorder, accounting for $109 million in medical expenses each year in the United States.

"If we can reduce the prevalence among the population, that would be a large amount of health-care resources that can be utilized," Laughon said.

For David and Mary Ollila of Chapel Hill, finding a cure for the disorder would not only save money but also heartache. Their daughter, Elizabeth, was born with gastroschisis four years ago.

In the early months of her pregnancy, Mary underwent a routine ultrasound that indicated problems. She underwent a more advanced test at UNC Hospitals to confirm gastroschisis.

"I had never heard of it before," Mary Ollila said. David Ollila, a surgical oncologist, had learned about the disorder in medical school, and together they pored over the literature to learn more. The diagnosis did not change Mary's pregnancy, but it raised concerns about the birth.

"I had to prepare for the fact that I was not going to be able to hold my baby right away," Mary Ollila said. Premature and underweight births are common with gastroschisis babies, and Elizabeth was born three weeks early, although she was a healthy 6 pounds.

Doctors swaddled the newborn and took her immediately to intensive care. About 80 percent of her small bowel was outside her abdomen. Her belly hadn't grown enough to accommodate all that intestine, so she had a surgery in which she was fitted with a silo attachment. David Ollila said it looked like a triangular coffee filter, and it guided the intestines slowly back into her belly over the course of four days.

Instead of nursing, Elizabeth received intravenous feedings. Gradually, as her bowels began adjusting, she was introduced to breast milk. After 3 1/2 weeks, she was discharged from the hospital.

"Now, she's an absolutely normal child," Mary Ollila said, noting that the only evidence is an unusual belly button where doctors made the incision to return her intestines.

"She's very proud of her stomach. She has two scars that make her very special."

Staff writer Sarah Avery can be reached at 829-4882 or savery@newsobserver.com.