Evaluation of Reproductive Parameters in Men with Solitary Testis.

PURPOSE: We evaluated reproductive parameters of men with a solitary testis compared to men with bilateral testes. MATERIALS AND METHODS: We conducted a cross-sectional case-control study comparing infertility evaluation parameters in men with a solitary testis to men with 2 testes. Men presenting for fertility consultation with semen analysis data collected within 90 days of clinical and hormonal assessment were included. Differences in semen and hormonal levels were characterized using descriptive statistics, multivariate analysis on matched semen parameters and evaluation of hypogonadism subtypes. RESULTS: A total of 837 men were identified. After applying exclusion criteria, we analyzed 29/39 men (74%) with a solitary testis and compared them to 656/798 men (82%) with 2 testes. A 1:1 match on sperm concentration and motility showed follicle-stimulating hormone was more elevated in men with a solitary testis (median 13.9 mIU/ml, IQR 5.8-24.2) than in men with bilateral testes (5.0, 3.4-9.8, p=0.009). Men with bilateral testes were uniformly azoospermic after a follicle-stimulating hormone level of 25.0 mIU/ml, whereas men with a solitary testis had some sperm in the ejaculate at follicle-stimulating hormone levels as high as 54.6 mIU/ml. Testosterone levels were similar between men with a solitary testis (median 381 ng/dl, IQR 248-500) and 2 testes (387, 296-507). The prevalence of compensated hypogonadism (high luteinizing hormone and normal testosterone) was higher in men with a solitary testis (8/29, 28%) than in men with bilateral testes (54/656, 8.2%, p=0.002). CONCLUSIONS: Men with a solitary testis have compensated pituitary strain as indicated by higher serum follicle-stimulating hormone and luteinizing hormone levels for the same testosterone and semen parameters compared to men with bilateral testes. Followup is needed to evaluate any detrimental consequences of this compensated state that may lead to pituitary burnout and decreased testicular function.

The microbiome of the infertile male.

PURPOSE OF REVIEW: Contrary to historic dogma, many tissues and organs in the human body contain a resident population of bacteria, fungi, and viruses collectively known as the microbiome. The microbiome plays a role in both homeostatic symbiosis and also pathogenic dysbiosis in a wide array of diseases. Our understanding of the relationship between the microbiome and male factor infertility is in its infancy but is slowly evolving. RECENT FINDINGS: Recent literature indicates that semen (and likely the testis) is not sterile and contains a distinct microbiome, and these changes in its composition are associated with alterations in semen quality and fertility status. Preliminary investigation indicates that manipulating the human microbiome may have implications in improving semen parameters and fertility. SUMMARY: In this review, we describe relationships between the microbiome and the genitourinary system, discuss the prior work on the relationship among bacteriospermia, leukocytospermia and male factor infertility, and summarize the current literature utilizing 16s rRNA-based next-generation sequencing on the seminal and testicular microbiome. We explore the specific microbial taxa implicated in various aspects of spermatic dysfunction and introduce preliminary evidence for therapeutic approaches to alter the microbiome and improve fertility status.