Helicobacter pylori infection and Hyperemesis gravidarum.: An institution-based case-control study

Background The etiology of Hyperemesis gravidarum (HG) is unclear. To test the hypothesis of an association between Helicobacter pylori infection and HG, an institution-based case-control study was performed at Aker University Hospital (AUH) during 1994-1999. Material and method From the same source population, 244 incident cases of HG and 244 pregnant women free of the disease (controls) were consecutively identified. Results H. pylori were noted in 105 cases and 58 control subjects. The presence of H. pylori increased the risk of HG more than two fold (OR = 2.42, 95% CI: 1.64-3.57, P < 0.001). This association was much stronger in Africans as compared to non-Africans (OR = 5.26, 95% CI: 1.04-26.57 vs. OR = 1.67, 95% CI: 1.07-2.61) after controlling for the confounding effect of maternal age. A gradient effect of exposure to H. pylori, determined by presence of specific IgG antibody in serum, and increased frequency of HG was present in Africans (test for linear trend P = 0.05) and non-Africans (test for linear trend P = 0.004). Conclusion These results indicate that H. pylori increase the risk of HG with a dose-response pattern and stronger in Africans.