The Role of Genital Tract Microbiome in Fertility: A Systematic Review

The human microbiome plays a crucial role in determining the health status of every human being, and the microbiome of the genital tract can affect the fertility potential before and during assisted reproductive treatments (ARTs). This review aims to identify and appraise studies investigating the correlation of genital microbiome to infertility. Publications up to February 2021 were identified by searching the electronic databases PubMed/MEDLINE, Scopus and Embase and bibliographies. Only full-text original research articles written in English were considered eligible for analysis, whereas reviews, editorials, opinions or letters, case studies, conference papers, and abstracts were excluded. Twenty-six articles were identified. The oldest studies adopted the exclusive culture-based technique, while in recent years PCR and RNA sequencing based on 16S rRNA were the most used technique. Regardless of the anatomical site under investigation, the Lactobacillus-dominated flora seems to play a pivotal role in determining fertility, and in particular Lactobacillus crispatus showed a central role. Nonetheless, the presence of pathogens in the genital tract, such as Chlamydia trachomatis, Gardnerella vaginalis, Ureaplasma species, and Gram-negative stains microorganism, affected fertility also in case of asymptomatic bacterial vaginosis (BV). We failed to identify descriptive or comparative studies regarding tubal microbiome. The microbiome of the genital tract plays a pivotal role in fertility, also in case of ARTs. The standardization of the sampling methods and investigations approaches is warranted to stratify the fertility potential and its subsequent treatment. Prospective tubal microbiome studies are warranted.

Appraisal of Experimental Methods to Manage Menopause and Infertility: Intraovarian Platelet-Rich Plasma vs. Condensed Platelet-Derived Cytokines

The first published description of intraovarian platelet-rich plasma (PRP) appeared in mid-2016, when a new experimental technique was successfully used in adult human ovaries to correct the reduced fertility potential accompanying advanced maternal age. Considering the potential therapeutic scope of intraovarian PRP would likely cover both menopause and infertility, the mainstream response has ranged from skeptical disbelief to welcome astonishment. Indeed, reports of intraovarian PRP leading to restored menses in menopause (as an alternative to conventional hormone replacement therapy) and healthy term livebirths for infertility patients (from IVF or as unassisted conceptions) continue to draw notice. Yet, any proper criticism of ovarian PRP applications will be difficult to rebut given the heterogenous patient screening, varied sample preparations, wide differences in platelet incubation and activation protocols, surgical/anesthesia techniques, and delivery methods. Notwithstanding these aspects, no adverse events have thus far been reported and ovarian PRP appears well tolerated by patients. Here, early studies guiding the transition of ‘ovarian rejuvenation’ from experimental to clinical are outlined, with mechanisms to explain results observed in both veterinary and human ovarian PRP research. Current and future challenges for intraovarian cytokine treatment are also discussed.

The Majority of Boys Having Orchidopexy for Congenital Nonsyndromic Cryptorchidism during Minipuberty Exhibited Normal Reproductive Hormonal Profiles

Introduction The activation of the hypothalamic–pituitary–gonadal axis that occurs in male minipuberty during the first 5 months of life is important for early germ cell development. Orchidopexy during minipuberty may improve fertility potential as the germinative epithelium may benefit from the naturally occurring gonadotropin stimulation. We hypothesize that most boys with congenital nonsyndromic cryptorchidism display normal reproductive hormonal profiles and histological findings during minipuberty. Methods We included boys with congenital nonsyndromic cryptorchidism who underwent orchidopexy at less than 160 days of age, having no potential for spontaneous resolution clinically. At surgery, testicular biopsies and reproductive hormones were collected and compared with normal reference values. We measured the germ cells (G/T) and type A dark spermatogonia number per tubule. Results Thirty-five boys aged 37 to 159 (median age: 124) days at orchidopexy were included, five were bilateral. G/T was below the normal lower range in 26% (9/35) of the cases. In six of these cases, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were above 97.5 percentile, whereas one case had FSH below 2.5 percentile. Totally, 97% (33/34, one FSH was missing) exhibited a normal LH/FSH ratio. LH was more often above 97.5 percentile than FSH: 34% (12/35) versus 3% (1/34, p < 0.001). Inhibin B was below 2.5 percentile in 17% (6/35) of cases who all proved FSH above normal mean and four had LH above normal mean. Conclusion Generally, reproductive hormonal profiles of the cryptorchid boys exhibited normal minipubertal pattern. Thus, 26% of the boys had reduced germ cell number, and transient hypogonadotropic hypogonadism could be suspected in few cases.

Appraisal of Experimental Methods to Manage Menopause and Infertility: Intraovarian Platelet-Rich Plasma vs. Condensed Platelet-Derived Cytokines

The first published description of intraovarian platelet-rich plasma (PRP) appeared in mid-2016, when a new experimental technique was successfully used in adult human ovaries to correct the reduced fertility potential accompanying advanced maternal age. Considering the potential therapeutic scope of intraovarian activated PRP and/or condensed platelet cytokines would likely cover both menopause treatment and infertility, the mainstream response has ranged from skeptical disbelief to welcome astonishment. Indeed, reports of restored menses in menopause (as an alternative to conventional hormone replacement therapy) and healthy term livebirths for infertility patients (either with IVF or as unassisted conceptions) after intraovarian PRP injection continue to draw notice. Yet any proper criticism of ovarian PRP applications will be difficult to rebut given the heterogenous patient screening, varied sample preparations, wide differences in platelet incubation and activation protocols, surgical/anesthesia techniques, and delivery methods. Notwithstanding these features, no adverse events have been reported thus far and ovarian PRP appears well tolerated by patients. Here, early research guiding the transition of &lsquo;ovarian rejuvenation&rsquo; from experimental to clinical is outlined. Likely mechanisms are presented to explain results observed in both veterinary and human ovarian PRP research. Current and future challenges for intraovarian cytokine treatment are also discussed.

Systematic Analysis of Breed, Methodological, and Geographical Impact on Equine Sperm Progressive Motility

Over the past five decades, there has been increasing evidence to indicate global declines in human semen quality. Parallel adverse trends measured in male animals indicate a potential environmental aetiology. This study evaluated the progressive motility (PM) of stallion ejaculate through a systematic review and meta-analysis. A total of 696 estimates of equine PM from 280 studies, which collected semen samples between the years 1990 and 2018, were collated for meta-analysis. The method of motility analysis, breed, season of collection, and geographical location were extracted. Simple linear regression determined temporal trends in stallion PM. Studies using microscopy estimated PM to be significantly greater compared to computer-automated methods (p ≤ 0.001). For Arabian breeds, PM was consistently higher than other breeds. Over time, there was a significant decline in PM for studies from Europe (n = 267) but a significant increase for studies from North America (n = 259). Temporal trends indicate the fertilising capacity of equine ejaculate has remained consistently high in the last three decades. That being so, variations observed suggest methodological, geographical, and individual stallion differences may significantly influence actual and reported stallion fertility potential.

The Power of Fertility and Its Importance for the Concept of Sustainable Development

Demographic changes are one of the indicators of sustainable development, expressed by the value of the natural increase in the human population, resulting directly from the fertility level, which is the subject of this article. Human fertility is a complex potential conditioned by the environmental, social, and economic factors. The multi-dimensional relations of fertility that may affect its level, constitute an unlimited field of research, study, and analysis. The inter-disciplinary scope of fertility research conducted by the authors has shown that fertility is an issue that, in its historical, social, political, and medical aspects, has the potential of contributing to societal development and raising the standard of living. The aim of this article is to answer the question: whether and how the fertility of an individual has an impact on the idea of sustainable development. To achieve this, the available literature was analysed and synthesised, as well as supplemented with information provided by experts in the field. The article incorporates presentations of selected fertility determining factors, methods of measuring fertility potential, and diverse contexts, such as the impact of fertility on history and its relationship with the freedom of the human individual. Moreover, the authors present the relationship between the fertility of an individual, and the assumptions and postulates of the idea of sustainable development.