Updated

More than half of women of childbearing age who are not using birth control (search) and may become pregnant drink alcohol and may be putting their unborn child at risk for fetal alcohol syndrome (search), according to a new CDC report.

In addition, the report shows that about one in 10 pregnant women report drinking alcohol.

Researchers say it’s the first time they’ve looked at alcohol use among women who might become pregnant, and the results suggest that better efforts are needed to inform women about the adverse effects of alcohol on pregnancy.

Fetal alcohol syndrome is considered the most preventable type of birth defect that affects brain development and growth. The condition causes behavioral and developmental abnormalities in the fetus by drinking alcoholic beverages during pregnancy.

Researchers say abnormal brain development as a result of drinking during pregnancy may occur as early as three to six weeks of gestation, a period in which most women might not realize they are pregnant.

No level of alcohol use during pregnancy has been found to be safe, and researchers say women who are pregnant or might become pregnant should not drink alcohol.

Alcohol and Pregnancy Don’t Mix

In the study, which appears in the Dec. 24 issue of Morbidity and Mortality Weekly Report, CDC researchers analyzed the results of the 2002 Behavioral Risk Factor Surveillance System survey, which included more than 64,000 women aged 18-44.

Of these women, 2,689 said they were pregnant. Researchers determined that an additional 4,404 women might become pregnant because they were not using any birth control and said they wanted a pregnancy, did not care if pregnancy occurred, did not think they could become pregnant, or did not use birth control for other reasons.

The analysis showed that drinking patterns among women who might become pregnant were similar to patterns found among other women. For example:

—Approximately 10 percent of pregnant women use alcohol, and about 2 percent engage in binge drinking or frequent use of alcohol.

—The prevalence of binge drinking was more than 12 percent in women who reported not using birth control and therefore might become pregnant.

—The number of women who reported frequent drinking (seven or more drinks per week) or binge drinking was about 13 percent for both childbearing-aged women and those who might become pregnant. Binge drinking is defined as five or more drinks on any one occasion.

—Use of any alcohol was reported by 53 percent of women of childbearing age overall and 55 percent for women who might become pregnant.

Researchers say the rates of drinking during pregnancy found in this report are similar to those found in previous reports.

By Jennifer Warner, reviewed by Brunilda Nazario, MD

SOURCE: Morbidity and Mortality Weekly Report, Dec. 24, 2004; vol 53: pp 1178-1180. News release, CDC.