No Histopathological Evidence of Inflammation Despite Molecular Detection of Schistosoma spp. and Sexually Transmitted Pathogens in Placental Parenchyma Specimens with Limited Membrane Sampling from West African Women with Uncomplicated Pregnancies.

BACKGROUND

Placental infections caused by Schistosoma spp. and sexually transmitted microorganisms can adversely impact pregnancy outcomes. However, the association between molecular detection of these pathogens in placental tissue and corresponding histopathological inflammation remains unclear, particularly in sub-Saharan African populations.

METHODS

In this cross-sectional study, placental parenchyma specimens with limited membrane sampling were collected from 103 Ivorian and Ghanaian mothers without known pregnancy or birth complications. Tissue pieces adjacent to PCR-tested samples were analyzed by real-time PCR targeting Chlamydia trachomatis, Mycoplasma hominis, Neisseria gonorrhoeae, Schistosoma spp., Streptococcus agalactiae, Trichomonas vaginalis, Ureaplasma parvum and Ureaplasma urealyticum. Corresponding adjacent tissues were examined by routine histopathology, supplemented with immunohistochemistry when higher pathogen DNA quantities were detected, to assess inflammatory changes.

RESULTS

Real-time PCR detected U. urealyticum in 15 out of 103 cases (14.6%, ±0.7%), U. parvum in 13 (12.6%, ±0.6%), S. agalactiae in 11 (10.7%, ±0.5%), the S. haematobium complex in four (3.9%, ±0.2%), M. hominis in four (3.9%, ±0.2%), confirmed N. gonorrhoeae in two (1.9%, ±0.1%) and non-confirmed N. gonorrhoeae in one (1.0%, ±0.1%), T. vaginalis in two (1.9%, ±0.1%), and C. trachomatis (non-lymphogranuloma venereum serovar) in one (1.0%, ±0.1%). Overall, pathogen DNA levels were low, with only four positive PCR results yielding cycle threshold (Ct) values below 30 and none below 25. Histopathological examination revealed no relevant inflammatory changes in any samples.

CONCLUSIONS

Placental parenchyma tissues with limited membrane sampling testing positive for Schistosoma spp. or sexually transmitted pathogens by molecular methods demonstrated no corresponding histopathological inflammation. These findings warrant confirmatory studies to better characterize potential region-specific placental infection phenotypes and their clinical significance.