Potential benefits versus hazards of herbal therapy during pregnancy; a systematic review of available literature

The use of herbal medicine has considerably grown worldwide in the past two decades. Studies have shown that the prevalence of herbal diet therapy in pregnancy ranged from 1% to 60% in different societies. Many clinical reports have shown that some herbal medicines may have toxic effects on pregnant women and their fetuses because active ingredients of some medicinal plants can readily pass through the biological barriers (e.g., placental barrier). In the present study, we aimed to systematically review the literature to discover potential benefits versus the hazards of herbal therapy during pregnancy. For this purpose, a comprehensive literature review was performed, and after the literature search and selection of the appropriate documents, the desired data were extracted and reported. From 35 articles with a total of 39,950 study population, the results showed that some medicinal plants could cause severe toxicity on mothers and fetuses, in addition to abortion during pregnancy. It was also shown that some plants may lead to developmental abnormalities or fetal death. Findings of this survey showed that some herbal medicines have toxic, teratogenic, and abortive potential, particularly in the first trimester of pregnancy because active ingredients of some medicinal plants are able to pass through the placental barrier and reach the fetus.