Increased susceptibility to Helicobacter pylori infection in pregnancy

Helicobacter pylori plays a major role in abdominal symptoms and gastroduodenal pathology, including gastric cancer. Pregnancy has been associated with changes in both humoral and cell-mediated immunity. These changes include alterations in the various classes of antibodies during different gestational periods. It has been previously suggested that these alterations may expose pregnant women to an increased risk of infection with this microorganism.

To further investigate this hypothesis, we assayed sera from 229 asymptomatic pregnant women for the presence of H.-pylori-specific immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies by means of a commercially available serum ELISA test (Malakit, Biolab, Belgium). Both tests were previously validated in large series of H.-pylori-positive and -negative subjects. While the presence of H.-pylori-specific IgG antibodies is only a marker for a "chronic" infection with this bacterium and therefore no indicator of the time of acquisition of the infection, specific IgM antibodies are a more specific marker for a recently acquired infection with H. pylori. Results were compared with those previously obtained in asymptomatic, healthy, nonpregnant individuals.

One hundred twenty of 229 women (52.4%) and 55/118 nonpregnant subjects (46.6%) were seropositive for H.-pylori-specific IgG antibodies (P > 0.3). Out of these 120 IgG-antibody-positive women, 36 (30%) were positive for H.-pylori-specific IgM antibodies, as were 25/109 (22.9%) in the IgG-antibody-negative group (P > 0.3). Overall, 61/229 (26.6%) of the pregnant women had recently been infected with H. pylori, compared with 11% of the healthy, nonpregnant population (P > 0.01).

Our observations confirm the possibility of an increased susceptibility to H. pylori infection in pregnancy. Additional studies are necessary to further understand the immune response to H. pylori in pregnancy.