Miscarriage is one of the fundamental complications occurring in pregnant women. Many fastidious and uncultivated bacterial species are related to miscarriage and have a significant role in the infection. The association between inverse pregnancy outcomes and infections of abnormal bacteria has been rarely investigated. Therefore, this study aimed to determine Leptotrichia amnionii and Atopobium vaginae as a risk factor for miscarriage states. A total of 80 cervical swabs and blood samples were obtained from females (34 non-pregnant with recurrent spontaneous miscarriage, 11 pregnant who had previous miscarriage, and 35 without miscarriage as control) who were referred to a hospital in Baghdad city. The relationship between demographic characteristics and miscarriage groups indicates a positive association between the age of 30 years and >45 years and miscarriage states, while no significant association (p>0.05) was found for the other parameters compared with the control. Also, no association was observed between the levels of TORCH IgM , antiphospholipid (APL) IgM, and anticardiolipidin (ACL) IgM antibodies and spontaneous miscarriage. The findings of RT-PCR detection revealed that, out of 45 samples of recurrent spontaneous miscarriage, 17 were detected with high-risk of L. aminonia compared with two samples from the control group. Also, 7 samples of recurrent spontaneous miscarriage were shown to be infected with A. vaginae compared with five samples from the control group. The adjusted odd ratios (ORs) of L. anmionii for spontaneous miscarriage and pregnancy states were 7.89 (CI 95%, 1.60 - 39.00) and 9.43 (CI 95%, 1.43 - 61.9), respectively, with highly significant difference between the study groups compared with the control. While no significant result was recorded between the adjusted ORs of A. vaginae for spontaneous miscarriage and pregnancy states, which were 1.23 (CI 95%, 0.416 - 3.67) and 0.636 (CI 95%, 0.083 - 4.88), respectively, compared with the control.
