Effectiveness and safety of ginger in the treatment of pregnancy-induced nausea and vomiting.

OBJECTIVE Conventional antiemetics are burdened with the potential of teratogenic effects during the critical embryogenic period of pregnancy. Thus, a safe and effective medication would be a welcome addition to the therapeutic repertoire. This systematic review was aimed at assessing the evidence for or against the efficacy and safety of ginger (Zingiber officinale) therapy for nausea and vomiting during pregnancy. DATA SOURCES Systematic literature searches were conducted in 3 computerized databases (MEDLINE, EMBASE, and Cochrane Library), and the reference lists of all papers located were checked for further relevant publications. METHODS OF STUDY SELECTION For the evaluation of efficacy, only double-blind, randomized controlled trials (RCTs) were included. All retrieved clinical data, including uncontrolled trials, case reports, observational studies, and RCTs, were included in the review of safety. TABULATION, INTEGRATION, AND RESULTS Six double-blind RCTs with a total of 675 participants and a prospective observational cohort study (n = 187) met all inclusion criteria. The methodological quality of 4 of 5 RCTs was high. Four of the 6 RCTs (n = 246) showed superiority of ginger over placebo; the other 2 RCTs (n = 429) indicated that ginger was as effective as the reference drug (vitamin B6) in relieving the severity of nausea and vomiting episodes. The observational study retrieved and RCTs (including follow-up periods) showed the absence of significant side effects or adverse effects on pregnancy outcomes. There were no spontaneous or case reports of adverse events during ginger treatment in pregnancy. CONCLUSION Ginger may be an effective treatment for nausea and vomiting in pregnancy. However, more observational studies, with a larger sample size, are needed to confirm the encouraging preliminary data on ginger safety. LEVEL OF EVIDENCE I.