Chronic Endometritis and Uterine Endometrium Microbiota in Recurrent Implantation Failure and Recurrent Pregnancy Loss

Abstract

The aim of this study was to evaluate whether chronic endometritis (CE) and uterine endometrium microbiota were associated with repeated implantation failures (RIFs) and recurrent pregnancy losses (RPLs). In this prospective study, uterine endometrial specimens were obtained from 24 women with RIF, 27 with RPL, and 29 fertile control women. Immunohistochemical staining of CD138 for CE and 16S ribosomal RNA (rRNA) sequencing analysis for uterine endometrium microbiota were performed simultaneously. To assess CE, Liu’s method, McQueen scores and plasma cell count/10 mm2 were used. The frequency of CE (plasma cells > 5.15/10 mm2) was higher in women with RPL (29.6%) than in fertile controls (6.8%, p 2 in women with RPL (median 1.53, range 0–252.6, p p Lactobacillus iners (median 4.7%, range 0–99.9 vs. median 0%, range 0–100, p Ureaplasma species (36.3% vs. 8.6%, p Lactobacillus iners and Ureaplasma species may be associated with the etiology of CE.

Keywords

• chronic endometritis
• microbiota
• recurrent pregnancy loss
• repeated implantation failure
• uterine endometrium