Consistent evidence on the detrimental role of severe chronic endometritis on in vitro fertilization outcome and the reproductive improvement after antibiotic therapy: on the other hand, mild chronic endometritis appears a more intricate matter

In the last decade, different studies demonstrated a detrimental impact of chronic endometritis (CE) on the success of spontaneous conception and assisted reproduction technologies, as well as an improvement in reproductive outcomes after CE cure. Studies based on endometrial cultures and biomolecular techniques found variable alterations of the endometrial microbiome in CE, with the local proliferation of common gram-positive (i.e., streptococci, staphylococci), gram-negative (i.e., Escherichia coli, Klebsiella pneumoniae, Neisseria gonorrhoeae) or less commonly intracellular (Mycoplasma, Ureaplasma, Chlamydiae) or anaerobic bacteria (Bifidobacteria, Prevotella). Notwithstanding the growing attention from the scientific community, CE still represents an “uncertain matter” in terms of diagnosis, treatment, and reproductive implications.