Safety of Herbal Medicine Use During Pregnancy: A Systematic Review of a Priori and a Posteriori Evidence

Abstract

Introduction: The use of herbal remedies during pregnancy is common, yet data on their safety for both the mother and fetus are scarce. This systematic review aims to consolidate evidence on the safety and potential adverse effects of commonly used herbal medicines during gestation.

Methods: A systematic search of MEDLINE, Embase, and TOXLINE was performed for cohort studies, case-control studies, and case series reporting on maternal or fetal outcomes following herbal medicine exposure during pregnancy. Data on teratogenicity, miscarriage, preterm birth, and other adverse events were extracted.

Results: The review included 52 studies covering over 30 different herbs. For common herbs like ginger and cranberry, the evidence suggests they are likely safe for managing nausea and urinary tract infections, respectively. However, for herbs such as black cohosh, dong quai, and licorice, there is conflicting evidence or reports of potential adverse effects like uterine stimulation or hormonal disruption. High-quality data for most herbs were severely lacking.

Discussion: The safety profile for many herbal medicines in pregnancy remains largely unknown. The lack of regulation and standardization of herbal products poses an additional risk. Healthcare providers should adopt a cautious approach and counsel pregnant women against using herbs with undocumented safety.

Conclusion: While a few herbs appear safe for specific indications in pregnancy, robust safety data is missing for the majority. Clinical guidance should prioritize evidence-based caution.