Sept. 25, 2003 -- A group of researchers in China is warning women about using the popular herbal remedy ginseng during the first few months of pregnancy.
Animal studies from the Chinese University of Hong Kong suggest that early exposure to the herbal remedy is capable of causing malformations in rat embryos. More study is needed, the researchers say, to determine if ginseng can cause fetal growth problems in humans. But in the meantime they urge pregnant women to be cautious about using the supplement, especially during their first trimester.
Ginseng is widely used in China, and to a lesser extent in the United States, for relief from stress and fatigue. It is also believed to improve mental and physical performance, and some people think it has anticancer properties. Because an herbal remedy is considered a food supplement and not a drug in the U.S., marketers of ginseng are not required to prove that their product is safe or effective.
"Pregnant women might take ginseng because they think it is good for their pregnancy and may not be aware that there could be unknown harmful effects," researcher Dr. Louis Y. Chan, says in a news release.
"Before more information in humans becomes available, women should be cautious about using ginseng in the first three months of pregnancy and it is always advisable for pregnant women to consult their doctor before taking any herbal supplement."
More Exposure, More Defects
In their study, Chang and colleagues showed impaired development in rat embryos exposed to one of the principal active components of ginseng, known as ginsenoside Rb1. The higher the exposure, the greater the developmental impairment, with embryos exposed to the highest doses having significantly shorter body lengths and less muscle cells. The findings are published in the Sept. 25 issue of the journal Human Reproduction.
Ginsenoside Rb1 is one of roughly two dozen ginsenosides present in commercially available ginseng. Chan said it is not yet clear whether the other ginsenosides can also cause fetal abnormalities or whether the abnormalities would occur with lower doses than those tested in their study.
Most Herbs Untested
The March of Dimes estimates that 60 million Americans use herbal supplements, and surveys show that many do not tell their physicians about them.
Few studies have been conducted testing the safety of herbal remedies during pregnancy, and the March of Dimes web site lists more than 50 that should not be used by pregnant women. They include popular herbal supplements like black cohosh, echinacea, and kava kava, as well as common herbs like ginger root and fennel seed.
Ginseng is not listed, but fetal development expert Jan M. Friedman, MD, PhD, tells WebMD that this doesn't mean it is safe.
"Most of these products have not been tested, so we don't know whether or not they are safe," she says. "It is best to avoid using them, or any other unnecessary medication, during pregnancy."
Friedman says the common misconception that "natural" means "safe" is particularly dangerous during pregnancy.
"It is worth pointing out that alcohol is a natural product that we know can cause birth defects when taken in large amounts during pregnancy," she says. "Similarly, tobacco, cocaine, and heroin are all natural products that should be avoided during pregnancy."