Seminars in reproductive medicine最新文献

Anti-Müllerian hormone (AMH) is secreted by Sertoli cells and is responsible for the regression of Müllerian ducts in the male fetus as part of the sexual differentiation process. Serum AMH concentrations are at their lowest levels in the first days after birth but increase after the first week, likely reflecting active Sertoli cell proliferation. AMH rises rapidly in concentration in boys during the first month, reaching a peak level at ∼6 months of age, and it remains high during childhood, then they will slowly decline during puberty, falling to low levels in adulthood. Serum AMH measurement is used by pediatric endocrinologist as a specific marker of immature Sertoli cell number and function during childhood. After puberty, AMH is released especially by the apical pole of the Sertoli cells toward the lumen of the seminiferous tubules, resulting in higher levels in the seminal plasma than in the serum. Recently, AMH has received increasing attention in research on male fertility-related disorders. This article reviews and summarizes the potential contribution of serum AMH measurement in different male fertility-related disorders.

Although epidemiology shows that both men and woman can experience infertility, the female partner usually experiences most of the diagnostic and therapeutic burden. Thus, management of couple infertility is a unique example of gender inequality. The use of exogenous gonadotropins in assisted reproductive technology (ART) to induce multifollicular growth is well consolidated in women, but the same is not done with the same level of confidence and purpose in infertile men. Indeed, the treatment of idiopathic male infertility is based on an empirical approach that involves administration of the follicle-stimulating hormone (FSH) in dosages within the replacement therapy range. This treatment has so far been attempted when the endogenous FSH serum levels are within the reference ranges. According to the most recent evidence, a “substitutive” FSH administration may not be effective enough, while a stimulatory approach could boost spermatogenesis over its basal levels without adverse extragonadal effects. This article aims to describe the rationale behind the empirical application of gonadotropins in couple infertility, highlighting the need for a change in the therapeutic approach, especially for the male partner.

Obesity affects nearly 40% of reproductive-aged women and has serious implications for women's overall and reproductive health. Women with an elevated body mass index (BMI) have higher rates of anovulation and irregular menses, lower success with fertility treatment, and significantly higher rates of pregnancy complications, such as hypertension/preeclampsia, gestational diabetes, and preterm delivery. Many studies have also shown an association between obesity and early pregnancy loss. However, the causal association between BMI and miscarriage has not been elucidated, likely due to the multifactorial effects that BMI may have on early pregnancy development. In addition, BMI as an isolated variable fails to capture other relevant confounding health risk factors, such as nutrition, physical activity, and insulin resistance. In this review, we will summarize the current literature demonstrating the association between BMI and miscarriage, highlight the research that attempts to explain the association, and finally provide data on therapeutic interventions to improve reproductive outcomes in women suffering from obesity and early pregnancy loss.

In recent years, the study of the human microbiome has surged, shedding light on potential connections between microbiome composition and various diseases. One specific area of intense interest within this research is the female reproductive tract, as it holds the potential to influence the process of embryo implantation. Advanced sequencing technologies have delivered unprecedented insights into the microbial communities, also known as microbiota, residing in the female reproductive tract. However, their efficacy encounters significant challenges when analyzing low-biomass microbiota, such as those present in the endometrium. These molecular techniques are susceptible to contamination from laboratory reagents and extraction kits, leading to sequencing bias that can significantly alter the perceived taxonomy of a sample. Consequently, investigating the microbiota of the upper female reproductive tract necessitates the exploration of alternative methods. In this context, the current review delves into the application of culturomics in unraveling the upper female reproductive tract microbiota. While culturomics holds value in research, its transition to routine clinical practice appears remote, at least in the foreseeable future.

In recent years, there has been a growing interest in identifying subcellular causes of male infertility, and sperm DNA fragmentation (SDF) research has been at the forefront of this focus. DNA damage can occur during spermatogenesis due to faulty chromatin compaction or excessive abortive apoptosis. It can also happen as sperm transit through the genital tract, often induced by oxidative stress. There are several methods for SDF testing, with the sperm chromatin structure assay, terminal deoxynucleotidyl transferase d-UTI nick end labeling (TUNEL) assay, comet assay, and sperm chromatin dispersion test being the most commonly used. Numerous studies strongly support the negative impact of SDF on male fertility potential. DNA damage has been linked to various morphological and functional sperm abnormalities, ultimately affecting natural conception and assisted reproductive technology outcomes. This evidence-based review aims to explore how SDF influences male reproduction and provide insights into available therapeutic options to minimize its detrimental impact.

Studies have proven the significance of microbial communities in various parts of the human body for health. In recent years it has been discovered that the uterine cavity is not sterile, and endometrium has its own microbiome which appears to have an impact on female fertility and gynecological pathologies. Lactobacillus has shown to dominate the microbial profile in the uterus and is considered an indicator of a healthy uterine environment. Yet, many argue that the Lactobacillus dominance is due to vaginal contamination during the sampling process. To date there is no clearly defined healthy endometrial microbial profile, which is largely due to the fact that determining the microbial community from the endometrium is complicated, and there is currently no consensus on sampling methods for the endometrial microbiome. As a result, this restricts ability to replicate discoveries made in other cohorts. Here we aim to give an overview of the sampling methods used and discuss what impedes the endometrial microbiome studies as well as how to reach a consensus on the study design. This knowledge could be incorporated into the future research and the knowledge on endometrial microbiome could be included into the diagnostics and treatment of female reproductive health.

In this Seminar, we present an overview of the current and emerging methods and technologies for optimizing the man and the sperm sample for fertility treatment. We argue that sperms are the secret to success, and that there are many avenues for improving both treatment and basic understanding of their role in outcomes. These outcomes encompass not just whether treatment is successful or not, but the wider intergenerational health of the offspring. We discuss outstanding challenges and opportunities of new technologies such as microfluidics and artificial intelligence, including potential pitfalls and advantages. This article aims to provide a comprehensive overview of the importance of sperm in fertility treatment and suggests future directions for research and innovation.

Since the end of the last century, several reports have suggested that semen quality is declining, especially in Western countries. Furthermore, cross-sectional studies using similar protocols have suggested regional differences in semen quality of young and fertile men. Reasons for these regional differences and local adverse trends in semen quality are unknown, but environmental factors are suspected to have a role. Besides adulthood environmental exposures, those occurring during testicular development may also affect semen quality. Longitudinal follow-up studies and mixture risk analyses are needed to study the effect of fetal, childhood, and adult life environment on semen quality.

Nonobstructive azoospermia (NOA) is among the most common causes of male infertility. For men with NOA seeking fertility treatment, microdissection testicular sperm extraction (microTESE) is the best option for retrieving sperm, which can be used with in vitro fertilization-intracytoplasmic sperm injection to achieve pregnancy in their partner. With the aid of the operating microscope, microTESE allows for thorough evaluation of the testis tissue and selection of seminiferous tubules that appear most capable of sperm production. Rates of success with microTESE vary depending on the underlying cause of NOA and the center at which the procedure is performed. Not all patients are candidates for microTESE, and those who are candidates should be counseled on the likelihood of sperm retrieval and the potential for changes in postoperative testis function.