The effectiveness and safety of ginger for pregnancy-induced nausea and vomiting: a systematic review

Background: Ginger has been used throughout the world as a therapeutic agent for centuries. The herb is increasingly used in Western society also, with one of the most common indications being pregnancy-induced nausea and vomiting (PNV). Objectives: To examine the evidence for the safety and effectiveness of ginger for PNV. Methods: Randomised controlled trials (RCTs) of ginger and PNV were sourced from CINAHL, the Cochrane library, MEDLINE and TRIP. The methodological quality of RCTs was assessed using the Critical Appraisal Skills Programme (CASP) tool. Results: Four RCTs met the inclusion criteria. All trials found orally administered ginger to be significantly more effective than placebo in reducing the frequency of vomiting and intensity of nausea. Adverse events were generally mild and infrequent. Conclusion: The best available evidence suggests that ginger is a safe and effective treatment for PNV. However, there remains uncertainty regarding the maximum safe dosage of ginger, appropriate duration of treatment, consequences of over-dosage, and potential drug-herb interactions; all of which are important areas for future research