Background and Aim: Several factors, including abrupt rise of HCG or female sex hormone has been suggested in the development of Hyperemesis gravidarum (HG). However some authors believe that infectious agents, especially Helicobacter pylori (H.pylori) are responsible for HG. In this study, frequency of H.Pylori antibody was compared between HG and non-HG pregnant women.

Patients and Methods: In this case-control study, 30 pregnant women with HG and 30 non-HG pregnant women who had referred to the clinics of Iran University of Medical Sciences were studied. IgG anti- H.Pylori antibody was evaluated among the two groups. Statistical anatylis was carried out using t-test, Chi-square test and Fischer’s exact test.

Results: Mean (±SD) age of case and control groups was 24±5 years and 26.8±5.1 years, respectively (NS). There were no significant differences between two groups regarding age, gravity and parity. Fifteen (50%) pregnant women with HG and 7 (23.3%) non-HG women were anti H.pylori positive which was statistically significant.

Conclusion: H.pylori may have potential role in developoing HG. So, it is recommended that those women who like to get pregnant in the near future, should be evaluated for HP and to be treated if tests are positive.