Microbiome, Infection and Inflammation in Infertility

Abstract

The implantation mechanism and process are very complex and require a precise interac‐ tion between the embryo and endometrium. The failure to implant is thought to be due to implantation environment factors or embryonic factors. A suitable condition of the uterine cavity is essential for successful reproduction. Inflam‐ mation can be a part of the normal physiologic process during implantation; however, there are also pathologic sources of inflammation that can adversely affect the uterine cavity and endometrial receptivity. Chronic Endometritis is usually asymptomatic and is defined histologically by the pres‐ ence of plasma cells in an endometrial biopsy. It is mostly associated with the gonorrheal or chlamydial also non-sexually transmitted infections including E-coli, streptococcus, staphylococcus, enterococcus faecalis, mycoplasma, urea plasma and yeast. However, of‐ ten a causal organism can not be identified. Available evidence suggests that chronic subclinical endometritis is relatively common in women with symptomatic lower genital tract infections, including cervicitis and recur‐ rent bacterial vaginosis and may not be altogether rare even in asymptomatic infertile women. Mucopurulent cervicitis is highly associated with chlamydial and mycoplasma infections and both organisms, in turn, are associated with chronic endometritis, which likely plays a role in the pathogenesis of tubal factor infertility. There is also a growing interest in the Microbiome of the reproductive tract. The Vaginal and Uterine Microbiome have been partially characterized and shown to be related to ob‐ stetric outcomes. Given the large number of unexplained IVF failures, it is reasonable to consider the uterine Microbiome and its impact on female fertility. Although routine serologic testing, cervical cultures and endometrial biopsies may be dif‐ ficult to justify, further evaluation and treatment are appropriate and prudent in infertile women with clinical cervicitis, chronic or recurrent bacterial vaginosis or other symptoms that suggest pelvic infection as well as in women with unexplained IVF failures. Compared to culture-dependent methods, culture-independent methods are estimated to have increased bacterial detection in the uterine cavity by about 50% and increased num‐ © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. ber of detected species by up to fivefold. The detection of bacteria in the intrauterine cavi‐ ty by PCR, in the absence of signs of infection, confirms the proposition of a non-sterile uterus. This chapter will focus on chronic endometritis, uterine microbiome and hydrosalpinges and will review the diagnosis, pathophysiology and the recommended treatments of these specific inflammatory processes that contribute to implantation failure.