MetroGel-Vaginal and Pregnancy
Although MetroGel-Vaginal (metronidazole vaginal gel) is a pregnancy Category B medicine and may be safe for use in pregnancy, there are some concerns that this drug may increase the risk for certain types of cancer. However, this medication is approved to treat bacterial vaginosis, a condition that may cause potentially serious problems during pregnancy. Thus, the benefits of the drug typically outweigh the potential risks.
Can Pregnant Women Use MetroGel-Vaginal?
MetroGel-Vaginal® (metronidazole vaginal gel) is a prescription medication used for the treatment of bacterial vaginosis. Even though metronidazole is a pregnancy Category B medication, it is not clear if it is safe for use during pregnancy.
There is some concern about the carcinogenic (cancer-causing) potential of metronidazole products, including MetroGel-Vaginal, when used during pregnancy. However, because bacterial vaginosis is a risk factor for some serious problems during pregnancy, the potential risks of the drug will likely be outweighed by the benefits.
What Is Pregnancy Category B?The U.S. Food and Drug Administration (FDA) uses a category system to classify the possible risks to a fetus when a specific medicine is taken during pregnancy. Pregnancy Category B is given to medicines that have not been adequately studied in pregnant humans, but do not appear to cause harm to the fetus in animal studies.
Metronidazole, the active ingredient in MetroGel-Vaginal, crosses the placenta. In general, animal studies have failed to show that metronidazole causes problems during pregnancy; however, one study suggested that metronidazole injected into the abdominal (stomach) cavity might cause miscarriages. Surveys and other similar types of studies in humans seem to suggest that metronidazole probably does not cause birth defects.
There is some concern that exposure to metronidazole during pregnancy might increase the risk of childhood or even adult cancers. Metronidazole increases the risk of certain cancers in mice and rats; it is unknown if the same is true for humans. Studies have failed to consistently show that metronidazole exposure does or does not increase the risk of childhood cancers.
More importantly, however, bacterial vaginosis is a risk factor for preterm delivery and low birth weights. This means that it is especially important to treat bacterial vaginosis in pregnant women. So, in many situations, the risks of the drug are probably outweighed by the potential benefits.