Chronic endometritis is associated with an altered microbiome, but what about treatment and clinical outcomes?

Oil-based contrast for hysterosalpingography-regulated Th1/Th2-type cytokines and alleviated inflammation in rats with LPS-induced chronic endometritis

AIM

The chronic endometritis (CE) prevalence in people experiencing infertility is 2.8-56.8%, pregnancy rates in patients with infertility increase after hysterosalpingography with oil-based contrast, but the effect and mechanism are not clear. Here, we analyzed the effects of intrauterine ethiodized poppyseed oil (EPO) bathing on a rat model of CE and the possible underlying mechanism.

METHODS

CE rats were induced by lipopolysaccharide (LPS) exposure, and rats were subjected to intrauterine bathing with EPO or phosphate-buffered saline (PBS) after model verification. Serum and uterus levels of IFN-γ, IL-4, TNF-α, and IL-1β were detected by ELISA kit, and the number of CD138⁺ and CD68⁺ cells and uterine IFN-γ, IL-4, TNF-α, IL-1β, and NF-κB P65 expression were detected by immunohistochemistry after bathing.

RESULTS

LPS exposure induced the typical CE phenotype with CD138⁺ phagocyte infiltration of the endometrial stroma. Compared with PBS bathing, bathing with EPO in CE rats showed decreases in the CD138⁺ and CD68⁺ cells populations and significant decreases in serum and uterine IFN-γ levels, moreover, uterine IL-4 levels were slightly higher, and the IFN-γ/IL-4(Th1/Th2-type cytokine ratio) in the uterus was significantly lower. Local IFN-γ, TNF-α, and NF-κB P65 expression in the endometrium was significantly downregulated, while IL-4 expression was upregulated.

CONCLUSION

Intrauterine oil-based contrast bathing significantly alleviated local inflammation in the rat CE model by downregulating NF-κB P65 expression, reducing IFN-γ (Th1), increasing IL-4 levels (Th2) in the endometrium, and regulating the Th1/Th2-type cytokine trends toward Th2.

Identification of Uterine Microbiota in Infertile Women Receiving in vitro Fertilization With and Without Chronic Endometritis

In vitro fertilization (IVF) is an important assisted reproductive technology in treating infertility, whose failure rate is still high. Studies suggested that uterine microbiota are related to women’s reproductive diseases and persisting intrauterine bacterial infectious conditions, such as chronic endometritis (CE), impairing the pregnant processes. However, the relationship between uterine microbiota and IVF outcomes is still an open question. In the present study, 94 patients diagnosed with infertility were enrolled and were divided into CE (E group, n = 25) and non-CE (NE group, n = 69) groups depending on the hysteroscopy and immunohistochemistry. Subsequently, E (Ep, n = 8 and Enp, n = 17) and NE (NEp, n = 41 and NEnp, n = 28) groups were divided into pregnancy and non-pregnancy groups depending on the IVF outcomes, respectively. The uterine fluids were collected and microbial profiles were examined through the V4 region of 16S rRNA gene high-throughput sequencing. The results demonstrated that patients with CE had significantly lower clinical pregnancy rate compared with the non-CE patients (32 vs. 58.42%, p = 0.0014). The relative abundances of Proteobacteria and Acidobacteria were higher in the non-CE group, whereas high abundances of Actinobacteria and Fusobacteria were observed in the CE group at the phylum level. At the genus level, high relative abundances of Gardnerella were observed in the CE group and non-pregnancy groups, which significantly referred to the negative IVF outcome. In conclusion, CE may be a key factor for the negative outcome after IVF, of which the uterine microbiota plays a pivotal role, and the microbial diversity in uterine may serve as a biomarker to forecast the success of IVF outcome.

Introducing intrauterine antibiotic infusion as a novel approach in effectively treating chronic endometritis and restoring reproductive dynamics: a randomized pilot study

The chronic nature of Chronic Endometritis (CE) along with the challenging management and infertility entailed, call for cutting-edge therapeutic approaches. This study introduces the novel treatment of intrauterine antibiotic infusion (IAI) combined with oral antibiotic administration (OAA), and it assesses respective performance against the gold standard treatment of OAA. Data sourced herein reports on treatment efficiency and fertility restoration for both patients aiming to conceive naturally or via In Vitro fertilization. Eighty CE patients, 40 presenting with recurrent implantation failure, and 40 with recurrent pregnancy loss, were enrolled in the IVF and the natural conception arm respectively. Treatment was subjected to randomization. Effectively treated patients proceeded with either a single IVF cycle or were invited to conceive naturally over a 6-month period. Combination of IAI and OAA provided a statistically significant enhanced effectiveness treatment rate (RR 1.40; 95%CI 1.07–1.82; p = 0.01). No statistically significant difference was observed regarding the side-effects rate (RR 1.33; 95%CI 0.80–2.22; p = 0.52). No statistically significant difference was observed for either arm regarding live-birth rate. Following an intention-to-treat analysis, employment of IAI corresponds to improved clinical pregnancy rate-albeit not reaching statistical significance. In conclusion, complimentary implementation of IAI could provide a statistically significant enhanced clinical treatment outcome.

Characterization of the vaginal and endometrial microbiome in patients with chronic endometritis

OBJECTIVE

To compare the endometrial and vaginal microbiome of women with and without chronic endometritis.

STUDY DESIGN

A cohort study with 60 patients undergoing assisted reproductive treatment with their own or donated gametes was undertaken. Vaginal and endometrial samples were taken in the cycle prior to embryo transfer. The endometrial and vaginal microbiome was analysed by mass sequencing of the V3V4 region of 16S rRNA gene. Bioinformatics analysis was performed using QIIME2 and MicrobiomeAnalyst packages. Alpha diversity, beta diversity and taxonomic characterization were compared between samples that tested positive and negative for chronic endometritis on CD138 immunohistochemistry.

RESULTS

Different bacterial communities were detected when vaginal and endometrial samples were analysed in patients with and without endometritis diagnosed using CD138 immunohistochemistry. In patients with endometritis, a higher alpha-diversity index was found in vaginal samples (p = 0.15 for the Shannon index) and significant differences were found in endometrial samples (p = 0.01 for the Shannon index). In the beta-diversity analysis, no significant differences were observed between the groups with and without endometritis. Vaginal and endometrial samples from women with endometritis showed a microbiome pattern that was not dominated by Lactobacillus spp. Relative abundance analysis identified Ralstonia and Gardnerella spp. in endometrial samples, and Streptoccoccus and Ureaplasma spp. in vaginal samples of patients diagnosed with chronic endometritis on CD138 immunohistochemistry. When comparing endometrial and vaginal samples diagnosed with endometritis on CD138 immunohistochemistry, both alpha diversity (p = 0.06 for the Shannon index and p = 0.08 for the Simpson index) and beta diversity (p < 0.001) showed significant differences. Lactobacillus spp. (p = 3.76E-4), Ralstonia spp. (p = 8.19E-4), Delftia spp. (p = 0.004) and Anaerobacillus spp. (p = 0.004) were identified in these sample groups.

CONCLUSION

These results demonstrate the existence of a characteristic vaginal and endometrial microbiota in patients with chronic endometritis. Different genera and species were identified in patients with and without chronic endometritis depending on whether the sample was endometrial or vaginal. There is a clear relationship between changes in the vaginal microbiome and chronic endometritis. The microbiota is a continuum throughout the female reproductive tract, so study of the vaginal microbiota could be useful for the diagnosis of diseases of the upper reproductive tract, such as chronic endometritis.

MODERN METHODS OF DIAGNOSIS AND TREATMENT OF CHRONIC ENDOMETRITIS, IN PREPARING PATIENTS FOR ASSISTED REPRODUCTIVE TREATMENT TECHNOLOGIES (LIT ERATURE REVIEW)

Since the chronic endometritis often leads to impaired reproductive function causing infertility, failed IVF attempts, miscarriage, and complicated pregnancy and childbirth, it has become not only medically relevant but also socially significant. For successful embryo implantation, the thickness of the endometrium should be at least 7 cm. Even though there is always a chance for embryo implantation, despite the endometrial hypoplasia, the attachment may be fragile, and such pregnancy may cease its development further on. Recently, in connection with an increase in the rate of developing allergic reactions, dysbacteriosis, and the emergence of drug-resistant strains of microorganisms, a search for new treatment methods to avoid these complications has begun. One of such methods in treating chronic endometritis, satisfying several requirements (efficiency, comfort, accessibility, safety), is the ultrasonic cavitation of the uterine cavity.

The impact of age beyond ploidy: outcome data from 8175 euploid single embryo transfers

PURPOSE

The rate of embryonic aneuploidy increases with increasing female age and is the primary cause of lower pregnancy and live birth rates (LBR) in older reproductive age women. This retrospective cohort study evaluates single euploid embryo transfers to determine whether an age-related decline in reproductive efficiency persists.

METHODS

A total of 8175 non-donor single embryo transfers (SET) after pre-implantation testing for aneuploidy (PGT-A) and cryopreservation were included. These were divided into five groups by patient age: < 35 years old (n = 3789 embryos transferred), 35-37 (n = 2200), 38-40 (n = 1624), 41-42 (n = 319), and > 42 (n = 243). Implantation rate (IR), clinical pregnancy rate (CPR), and LBR were calculated for each group as a percentage of embryos transferred and compared. CPR was also analyzed as a percentage of implanted pregnancies, and LBR as a percentage of clinical pregnancies, to determine when age has the greatest impact. These results were then adjusted for confounding variables via a multivariate logistic regression model.

RESULTS

Implantation rates negatively correlated with age. After adjusting for confounders, women 38 years or older had a significantly lower IR than those under 35 (OR 0.85, 95%CI 0.73-0.99 for 38-40 years old; 0.69, 0.53-0.91 for 41-42, and 0.69, 0.51-0.94 for > 42). These differences are also apparent in CPR and LBR. The rates of progression to clinical pregnancy and live birth did not differ significantly by age group. Other factors observed to affect IR independently were anti-Müllerian hormone (AMH), day of embryo transfer, and embryo morphology.

CONCLUSION

While selection of euploid embryos may be effective in overcoming a significant proportion of the age-related decline in reproductive efficiency, a decrease in IR, CPR, and LBR persists even when analyzing only euploid embryo transfers. The observed impact of aging is, therefore, independent of ploidy, as well as of other variables that affect reproductive efficiency. These results indicate that factors other than aneuploidy contribute to reproductive senescence.