title: Effects of ginger for nausea and vomiting in early pregnancy: a meta-analysis.
abstract: BACKGROUND
  Nausea and vomiting in early pregnancy (NVEP) is commonly encountered in family medicine. Ginger (Zingiber officinale) is a popular nonpharmacological treatment but consensus of its use is lacking.
  
  
  METHODS
  We conducted a meta-analysis of clinical trials using ginger for NVEP as published in PubMed and EMBASE, CINAHL, Cochrane Library, and all EBM reviews. Studies satisfying 3 criteria were selected: (1) randomized placebo-controlled design; (2) use of ginger or Z. officinale; and (3) extractable data on improvement in NVEP. Data were synthesized into pooled odd ratios based on the random effects model, and results were tabulated with the aid of Forest plots.
  
  
  RESULTS
  We identified 135 potentially relevant records; only 6 studies met the final criteria. Of the total 508 subjects, 256 and 252 subjects were randomly assigned to receive ginger and placebo, respectively. The use of ginger (∼1 g daily) for at least 4 days is associated with a 5-fold likelihood of improvement in NVEP. Heterogeneity among the clinical studies were acknowledged in the final interpretation of results.
  
  
  CONCLUSIONS
  Despite the widespread use of ginger in the diet, its clinic value and safety profile in treating NVEP is still unknown. Our meta-analysis suggests that ginger is an effective nonpharmacological treatment for NVEP.
authors.affiliation: the Department of Family Medicine and the Centre of Studies in Primary Care, Queen's University, Kingston, Ontario, Canada.
authors.forename: Maggie
authors.initials: M
authors.lastname: Thomson
authors.forename: Renee
authors.initials: R
authors.lastname: Corbin
authors.forename: Lawrence
authors.initials: L
authors.lastname: Leung
mesh_terms: D005260:Female; D020939:Zingiber officinale; D006801:Humans; D048968:Morning Sickness / Q000188:drug therapy* / Q000209:etiology; D008517:Phytotherapy; D028321:Plant Preparations / Q000627:therapeutic use*; D011247:Pregnancy; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors
chemical_list: D028321:Plant Preparations
keywords: Alternative Medicine; Complementary Medicine; Pregnancy; Prenatal Care; Primary Health Care