On the chequered history of vasectomy

Androgens in male contraception

Rates of unplanned pregnancies are high globally, burdening women and families. Efforts to develop male contraceptive agents have been thwarted by unacceptable failure rates, side effects and a dearth of pharmaceutical industry involvement. Hormonal male contraception consists of exogenous androgens which exert negative feedback on the hypothalamic-pituitary-gonadal axis and suppress gonadotropin production. This in turn suppresses testicular testosterone production and sperm maturation. Addition of a progestin suppresses spermatogenesis more effectively in men. Contraceptive efficacy studies in couples have shown male hormonal methods are effective and reversible, but also may come with side effects related to sexual desire, acne and serum cholesterol and inconvenient methods of dosing and delivery. Recently, novel androgens as potential contraceptive agents are being evaluated in early clinical trials and look to overcome these drawbacks. Here we summarize landmark studies of prototype male hormonal contraceptives, showcasing recent advances and future prospects in this important area of public health.

Post-Vasectomy Semen Analysis: Optimizing Laboratory Procedures and Test Interpretation through a Clinical Audit and Global Survey of Practices

PURPOSE

The success of vasectomy is determined by the outcome of a post-vasectomy semen analysis (PVSA). This article describes a step-by-step procedure to perform PVSA accurately, report data from patients who underwent post vasectomy semen analysis between 2015 and 2021 experience, along with results from an international online survey on clinical practice.

MATERIALS AND METHODS

We present a detailed step-by-step protocol for performing and interpretating PVSA testing, along with recommendations for proficiency testing, competency assessment for performing PVSA, and clinical and laboratory scenarios. Moreover, we conducted an analysis of 1,114 PVSA performed at the Cleveland Clinic's Andrology Laboratory and an online survey to understand clinician responses to the PVSA results in various countries.

RESULTS

Results from our clinical experience showed that 92.1% of patients passed PVSA, with 7.9% being further tested. A total of 78 experts from 19 countries participated in the survey, and the majority reported to use time from vasectomy rather than the number of ejaculations as criterion to request PVSA. A high percentage of responders reported permitting unprotected intercourse only if PVSA samples show azoospermia while, in the presence of few non-motile sperm, the majority of responders suggested using alternative contraception, followed by another PVSA. In the presence of motile sperm, the majority of participants asked for further PVSA testing. Repeat vasectomy was mainly recommended if motile sperm were observed after multiple PVSA's. A large percentage reported to recommend a second PVSA due to the possibility of legal actions.

CONCLUSIONS

Our results highlighted varying clinical practices around the globe, with controversy over the significance of non-motile sperm in the PVSA sample. Our data suggest that less stringent AUA guidelines would help improve test compliance. A large longitudinal multi-center study would clarify various doubts related to timing and interpretation of PVSA and would also help us to understand, and perhaps predict, recanalization and the potential for future failure of a vasectomy.

Reversible Contraceptive Potential of FDA Approved Excipient N, N-Dimethylacetamide in Male Rats

Development of an effective male contraceptive agent remains a challenge. The present study evaluates the potential of N, N-Dimethylacetamide (DMA), a FDA approved excipient as a male contraceptive agent. Male Sprague Dawley rats injected with DMA for a period of 8 weeks (one injection per week) showed a significant alteration of reproductive parameters. Furthermore, DMA treated animals showed complete infertility in a dose dependent manner, as no pups were born despite proper mating between females and DMA treated males. However, stopping the DMA treatment for a period of 8 weeks (after the initial treatment) restored the reproductive parameters to normal. Moreover, the fertility was resumed to normal as pups were born in the groups where DMA treatment was halted after initial DMA treatment. All these changes had no effect on the level of reproductive hormones FSH, LH and testosterone. Taken together, our results indicate that DMA acts in a reversible and non-hormonal manner to achieve contraception in rats. Therefore, repurposing the use of DMA could lead in a short time to an inexpensive and safer male contraceptive option.

Male Hormonal Contraception

The economic and public health burdens of unplanned pregnancies are evident globally. Since the introduction of the condom >300 years ago, assumptions about male willingness to participate in contraception, as well as concerns about failure rates and side effects, have stagnated the development of additional reversible male contraceptives. However, changing attitudes and recent research advances have generated renewed interest in developing reversible male contraceptives. To achieve effective and reversible suppression of spermatogenesis, male hormonal contraception relies on suppression of testicular testosterone and sperm production using an androgen-progestin combination. While these may be associated with side effects—changes in libido, weight, hematocrit, and cholesterol—recently, novel androgens and progestins have shown promise for a “male pill” with reduced side effects. Here we summarize landmark studies in male contraceptive development, showcase the most recent advances, and look into the future of this field, which has the potential to greatly impact global public health.

Recent Developments in Male Contraception

Unplanned pregnancies are an ongoing global burden, posing health and economic risks for women, children, and families. Advances in male contraception have been historically stymied by concerning failure rates, problematic side effects, and perceived market limitations. However, increased interest in reliable and reversible options for male contraception have resulted in resurgent efforts to introduce novel contraceptives for men. Hormonal male contraception relies on exogenous androgens and progestogens that suppress gonadotropin production, thereby suppressing testicular testosterone and sperm production. In many men, effective suppression of spermatogenesis can be achieved by androgen-progestin combination therapy. Small-scale contraceptive efficacy studies in couples have demonstrated effectiveness and reversibility with male hormonal methods, but side effects related to mood, sexual desire and cholesterol remain concerning. A number of novel androgens have reached clinical testing as potential contraceptive agents; many of these have both androgenic and progestogenic action in a single, modified steroid, thereby holding promise as single-agent contraceptives. Currently, these novel steroids hold promise as both a "male pill" and long-acting injections. Among non-hormonal methods, studies of reversible vaso-occlusive methods (polymers that block transport of sperm through the vas deferens) are ongoing, but reliable reversibility and long-term safety in men have not been established. Proteins involved in sperm maturation and motility are attractive targets, but to date both specificity and biologic redundancy have been challenges for drug development. In this review, we aim to summarize landmark studies on male contraception, highlight the most recent advances and future development in this important field of public health and medicine.

Vasectomy: a "seminal" analysis

Vasectomy is one of the most reliable and cost-effective permanent methods of contraception. Despite its popularity, certain issues pertaining to the procedure remain unresolved. Appropriate selection of candidates for vasectomy requires thorough counseling and screening, though a foolproof method of eliminating dissatisfaction and regret remains a mystery. Debate continues over the relative merits of the various techniques of isolating and sealing the vasal ends. Postoperative complication rates remain minimal regardless of the technique used, and no single strategy attempting to maximize patient compliance with postoperative semen analysis has enjoyed unmitigated success. Long-term consequences, other than regret, are rare. Finally, issues regarding residency training in the procedure and its impact on procedure morbidity are scarcely addressed in the literature. This study reviews the evolution of vasectomy as a contraceptive procedure and attempts to summarize current literature addressing these unresolved issues.