O-259 1.\tComparison of endometrial versus vaginal microbiota in 71 infertile patients

Abstract Study question 1.Mostly, endometrial microbiome probes are acquired by trans-cervical sampling using a “pipelle”. However, it is unclear, whether this approach “contaminates” the material. Summary answer 1.Vaginal and samples significantly different from each other with respect to (alpha-)diversity showing community be more polymicrobial. What known already 1. The female genital tract colonized continuum of microbiota, ranging typically diverse, but lower-biomass, bacterial communities in endometrium less higher-biomass, vagina (Chen et al., 2017). In reproductive-age women, vaginal mainly dominated lactobacilli (Ravel, 2011). By contrast, composition has remained well-characterized. With recent introduction next generation sequencing quantitative comprehensive picture begun emerge (Baker 2018). design, size, duration study was conducted at “novum, Zentrum für Reproduktionsmedizin”, Essen / Duisburg, Germany. Of 76 enrolled patients undergoing treatment,73 provided both swab biopsy same run between February 2020 March 2021. All analyses were carried out retrospectively. Information about pregnancy or delivery extracted medical records obtained telephone email interviews through June 2022. Participants/materials, setting, methods 1.Amplification V1-V2 16S rDNA regions “dus.ana, Düsseldorf Analytik”, Germany, QIAseq screening regional panels. CLC Microbial Genomic Workbench used assess composition, alpha diversity, microbial structure (PCoA). Pairs complete corresponding microbiota data available for 71 (two patient excluded due too low read counts probe, respectively). Main results role chance 1.Patients exhibiting mean age 35 years (range 26 – 42) body mass index (BMI) 24,5 18,8 38,7). 20 (28,2 %) diagnosed chronic endometritis (more than 1 plasmacyte per HPF) 15 (21,1 endometriosis. 40 participants found have undergone past miscarriages, 11 given birth children. 2.Abundance showed differences Lactobacillus sp., most pronounced L. jensenii gasserie. group non-lactobacilli only slightly enlarged group, encompassing G. vaginalis. regard diversity (Shannon entropy), (Kruskal-Wallis test). addition, distribution illustrated PCoA indicated that clustered together variance one dimension. far away grouped very disperse. Limitations, reasons caution 1.Group infertile an IVF center underlying clinical diagnosis studied retrospective setting. Wider implications findings 1.Trans-cervical “pipelle” provides which obviously polymicrobial - higher may harbor biological heterogeneity, hence functionality microbiome. Further studying correlation ongoing. Trial registration number 2021-1448