(NaturalNews) Gastroschisis is a birth defect in which the intestines, and sometimes other organs, develop outside the fetal abdomen and poke out through an opening in the abdominal wall. Long considered a rare occurrence, gastroschisis has mysteriously been on the rise over the last three decades. In fact, the incidence of the defect has soared, increasing two to four times in the last 30 years. But why?

Researchers think they've found the answer. The culprit behind the suffering of babies born with this condition appears to be the agricultural chemical atrazine. That's the conclusion of a study just presented at the annual meeting of the Society for Maternal-Fetal Medicine (SMFM) held in Chicago. 

Researchers at the University of Washington in Seattle were alerted to a higher than normal number of cases in of the birth defect in babies born in eastern Washington. So they began investigating to see if the increased incidence was due to some kind of environmental exposure in that area.

"Our state has about two times the national average number of cases of gastroschisis," Dr. Sarah Waller, one of the study's authors, said in a statement to the media. "The life expectancy for fetuses with this diagnosis is better than 90 percent; however it requires delivery at a tertiary care center with immediate neonatal intervention which often separates families and can cause serious financial and emotional stress."

The condition can lead to poor function of the bowel after delivery and potential long term feeding problems. Bottom line: babies with this birth defect must undergo the trauma of surgery right after birth. And while most survive, some babies with gastroschisis have significant damage to the bowel due to direct contact between the intestine and amniotic fluid or because the intestine was twisted. These infants may develop a condition known as "short gut" which can lead to stunted growth and a host of feeding and other problems.

For the new study, Dr. Waller and her research team went to work investigating all cases of live born infants with gastroschisis during the period between 1987 and 2006. They matched birth certificates with databases from the U.S. Geological Survey that revealed where agricultural spraying took place and what chemicals were used. It turns out the chemicals atrazine, nitrates, and 2, 4 dichlorophenoxyacetic acid were heavily sprayed in the area.

Of the 805 cases and 3,616 controls in the study, gastroschisis developed far more frequently among babies whose mothers lived less than 25 km from the site of high surface water that was specifically contaminated with one of the chemicals -- atrazine. What's more, the risk of gastroschisis was found to especially rise in babies of women who conceived in the spring, from March through May. Those are the months when use of the chemical is the most prevalent.

The problem with atrazine