Recreational drug use may raise birth defect risk

Women who use street drugs around the time of conception and early in pregnancy are likely to increase the chances their infants will be born with a defective closure of the abdominal wall through which the intestines protrude - a condition called Gastroschisis - according to researchers in Ireland.

"This has scientifically confirmed what people have suspected," Dr. John J. Morrison from University College Hospital, Galway, told Reuters Health. "There has been a recent large increase in the incidence of Gastroschisis, and particularly among young socially unsupported mothers."

In some ways, "the findings are not entirely surprising," Morrison said. "Methamphetamine and cocaine are pretty toxic compounds when investigated in embryos in animal studies. It is therefore very tenable that intake at the critical period of time around the time of conception, or the early first trimester of pregnancy, could be linked to major problems in fetal development."

Gastroschisis Gastroschisis is a congenital defect of the abdominal wall. It is similar to an omphalocele in appearance. An omphalocele, however, is a herniation of the abdominal contents through the umbilical cord, and is covered with a sac - while gastroschisis is a herniation through the abdominal wall (usually to the right of the umbilical cord), which does not involve the cord. In addition, in gastroschisis, the intestines (bowels) are exposed.

As in omphaloceles, the abdominal cavity may be small and replacement of the bowel into the cavity may require several weeks in which the abdominal cavity is gently stretched to accommodate the mass.

Morrison and his associates used hair analysis to assess mothers' drug use. They report in BJOG: an International Journal of Obstetrics and Gynaecology, that

10 of 22 women (45 percent) with a baby born with Gastroschisis had evidence of recreational drug use around conception or during the first trimester, compared with 2 of 25 women (8 percent) whose fetuses were known to be normal.

"While these findings are of association, and therefore not conclusive of causation, and while the numbers in this study are relatively small, this is the first time that objective measurements of maternal intake of recreational drug compounds at these critical periods of development for the fetus have been carried out," the team explains.

"The logical step to take now," Morrison added, "is to develop the use of these techniques further in a large cohort of Gastroschisis and to evaluate the potential relevance of this to other unexplained isolated fetal abnormalities."