Placental histological inflammation and reproductive tract infections in a low risk pregnant population in Latvia

Background. To investigate the correlation of reproductive tract infections (RTI) and endogenous vaginal flora at first antenatal consultation with placental histological inflammation. Methods. In a follow-up study, 154 low risk women with no miscarriage risk factors were examined for the presence of Neisseria gonorrhoeae, Trichomonas vaginalis, Chlamydia trachomatis, Ureaplasma urealyticum, Mycoplasma hominis, Gardnerella vaginalis, Streptococcus agalactiae (GBS), Staphylococcus aureus, Enterococcus faecalis (GDS) and bacterial vaginosis (BV). At delivery, outcome data were collected and the histology of the placenta was studied. Results. Some 85 (56.3%) of all pregnant women had RTI or endogenous vaginal flora. Placental histological inflammation correlated with genital tract colonisation with G. vaginalis (p =0.013), BV (p =0.031), S. aureus (p =0.04) and aerobic vaginitis (p =0.017). BV and BV-related G. vaginalis correlated with the presence of parietal and placental chorioamnionitis in 53.8 and 43.5% of cases. Genital tract colonisation with GDS and other aerobic flora in combination with inflammatory vaginitis correlated with the presence of funisitis in 33.3 and 40.0% of cases. Mycoplasmas increased the risk for intrauterine infection only when present in combination with other RTIs (p =0.023). Conclusion. Histological placental inflammation is associated with both BV and genital tract colonisation with aerobic bacteria, while funisitis is associated with colonisation of aerobic bacteria at first prenatal visit before the 17th gestational week.