Background: Listeria monocytogenes is one of the most important causes of abortion and postpartum infection in newborns. Because of the importance of L . monocytogenes in the health of pregnant women and newborn babies, the aim of this study was to determine the prevalence of these bacteria in pregnant women and to compare the level of prevalence between women with a history of abortion and with no a history of abortion.

Materials and Methods: In this study, 540 samples of pregnant women were provided from Arak Taleghani hospital. The samples were cultured in enrichment media, then L .monocytogenesis was isolated in specific media.

Results: Of clinical samples, 14 cases had Listeria monocytogenes. Of these samples, 8 cases in women had a history of abortion, while women with no history of abortion were 6 Most cases of positive culture were related to the age of 25 to 34 years, including 7 cases, the lowest cases were 35 to 44 years old including 3 women and 4 women were between 17 and 24 years old.

Conclusion: The study showed that Listeria monocytogenes can cause infection in pregnant women. The use of Phenotypic methods and specific media can apparently isolate listeria monocytogenes from healthy pregnant women.