Herbal therapies in pregnancy: what works?

The aim of this article is two-fold: to report the prevalence of herbal products used by pregnant women and to evaluate the evidence of efficacy and safety of the most popular remedies.

Of the 671 articles identified, 15 randomized controlled trials (RCTs) and 16 non-RCTs were eligible. Ginger was the most investigated remedy and it was consistently reported to ameliorate nausea and vomiting in pregnancy. Although raspberry, blue cohosh, castor oil, and evening primrose oil are believed to facilitate labor in traditional medicine, very few scientific data support such indication. Moreover, they have been associated with severe adverse events. Data on the safety of Hypericum perforatum in pregnancy or lactation are reassuring, whereas efficacy was demonstrated only in nonpregnant individuals. There is still insufficient evidence regarding the efficacy and safety of Echinacea, garlic, and cranberry in pregnancy.

Epidemiological studies reported a wide range of use of herbal remedies in pregnancy. Too few studies have been devoted to the safety and efficacy of singular herbs. With the exception of ginger, there are no consistent data to support the use of any other herbal supplement during pregnancy. Severe adverse events have been reported using blue cohosh and evening primrose oil.