title: Hyperemesis gravidarum and Helicobacter pylori infection: a systematic review.
abstract: OBJECTIVE
  To systematically review studies examining the relationship between hyperemesis gravidarum and Helicobacter pylori (H pylori) infection.
  
  
  METHODS
  A 1966 to January 2007 search using MEDLINE/PubMed, EMBASE, and Web of Science included MeSH terms: "Helicobacter pylori," "Helicobacter infections," "hyperemesis gravidarum," and the text words "nausea," "vomit," "pregnancy," and "Helicobacter." References of selected papers were examined for additional relevant studies.
  
  
  METHODS
  We evaluated studies investigating a relationship between hyperemesis gravidarum and H pylori infection. Studies were included in which the diagnosis of hyperemesis gravidarum was made at or before entry into the study, and H pylori diagnosis was made by serum antibody sample, gastric biopsy, saliva test, or stool sample. The search produced 169 titles; 22 were reviewed in further detail.
  
  
  RESULTS
  Fourteen case-control studies met established criteria, involving 1,732 participants and controls tested for H pylori infection. Studies were evaluated according to patient demographics and study methodology (case definition, exclusion criteria, H pylori testing). An estimate of the odds ratios with 95% confidence intervals was calculated by using a random effects model for dichotomous variables with review article software. Ten studies showed a significant association between hyperemesis gravidarum and H pylori infection. Odds ratios varied from 0.55 to 109.33; three results were less than 1.0. Tests for heterogeneity applied to several subgroups were considerable with values above 75% for all groups.
  
  
  CONCLUSIONS
  An association between hyperemesis gravidarum and H pylori infection is suggested by this systematic review. However, the considerable heterogeneity among studies highlights study limitations.
authors.affiliation: Department of Family Medicine, SMBD Jewish General Hospital, McGill University, Montreal, Canada. dgolberg@her.jgh.mcgill.ca
authors.forename: Deborah
authors.initials: D
authors.lastname: Golberg
authors.forename: Andrew
authors.initials: A
authors.lastname: Szilagyi
authors.forename: Lisa
authors.initials: L
authors.lastname: Graves
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D016001:Confidence Intervals; D005260:Female; D016481:Helicobacter Infections / Q000453:epidemiology*; D016480:Helicobacter pylori; D006801:Humans; D006939:Hyperemesis Gravidarum / Q000453:epidemiology*; D016017:Odds Ratio; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology*; D012307:Risk Factors