New research from the University of Chicago indicates that the number of pregnant women seeking treatment for methamphetamine use tripled between 1994 to 2006, HealthDay News reported May 21.

Researcher Mishka Terplan and colleagues analyzed data from federally funded treatment centers and found that methamphetamine use accounted for 8 percent of all admissions to treatment centers in 1994, but increased to 24 percent in 2006.

The prevalence of methamphetamine users was higher among pregnant women than among men or for nonpregnant women, the researchers found. Most of treatment admissions for pregnant women took place in the western United States, and among white women and unemployed women.

"Most women decrease or stop using during pregnancy," said Terplan, "but they're aware of the stigma associated with abuse behavior and they may be reluctant to seek care. They may also have concerns about losing their children."

The effects of methamphetamine use on fetal development are unclear, according to researchers. Some studies indicate that babies born to mothers using methamphetamine are smaller, Terplan said. One study shows that methamphetamine exposure may lead to microscopic structural brain changes in the children. However, it is not clear if there are any long-term effects from these changes.

The findings were published in the June 2009 issue of the journal Obstetrics & Gynecology.