This chapter discusses the mechanisms of action of hormonal male contraception, which suppresses the hypothalamic-pituitary-testis axis. When the intratesticular concentration of testosterone is subsequently suppressed to adequately low concentrations, spermatogenesis is arrested. Androgens are a necessary hormonal male contraceptive component because they not only suppress the hypothalamic-pituitary-testis axis, but also provide the male hormone necessary to maintain peripheral androgen functions. Past studies using testosterone alone and testosterone combined with progestins demonstrated contraceptive efficacy in the female partner at rates similar to combined hormonal female methods. Newer hormonal male contraceptive formulations and the alternative routes of administration are discussed, along with potential barriers, challenges, and opportunities for hormonal male contraceptive development. Novel methods that are safe, effective, reversible, user-friendly, and coitus-independent are intrinsic to equitably meet the various needs and limitations of an increasingly diverse population.

Objective

To determine whether a user-controlled sperm concentration test compared with standard semen analysis can effectively monitor spermatogenesis suppression for male contraception.

Design

Single center, prospective sub study of the ongoing clinical trial: "Study of daily application of Nestorone and testosterone combination gel for male contraception."

Setting

Research institute at an academic medical center.

Participant(s)

Couples participating in the male contraceptive clinical trial.

Interventions

None.

Main outcome measure(s)

The ability by participants to monitor sperm suppression to a threshold compatible with contraceptive efficacy utilizing a user-controlled test verified by sperm concentration determined by standard laboratory methods.

Result(s)

Thirty-eight men participating in a hormonal male contraceptive clinical trial provided multiple samples during spermatogenesis suppression for this substudy. Participants, employing a user-controlled test, correctly identified the absence of sperm (a negative test) in 100% of their laboratory-confirmed azoospermic samples (n = 122). Participants also identified 100% of samples (n = 73) with sperm >0.2 million/mL as positive. Sperm counts between 0.01 and 0.2 million/mL were identified as negative in 96% of samples. Trial participants noted the overall ease of using the test with respect to sample preparation, test timing, and result interpretation, and that they could accurately use this test at home without difficulty.

Conclusion(s)

Participants undergoing spermatogenesis suppression in a hormonal male contraceptive trial performed user-controlled test to determine whether their semen sperm concentration was ≤ or >0.2 million/mL. Compared with standard semen analyses, participants correctly identified 100% of samples with sperm counts >0.2 million/mL as positive (Sensitivity 100%). A positive result when the couple is using a male contraceptive method triggers the need for semen analysis by a laboratory while the couple uses another method of contraception. Participants correctly diagnosed samples ≤0.2 million sperm/mL as negative in 99% of samples (specificity 99%). A negative result indicates a sperm concentration ≤0.2 million/mL, well below the threshold of ≤1 million/mL offering contraceptive efficacy demonstrated by prior studies. At-home sperm concentration test would minimize the need for users to return to the clinic to monitor suppression of spermatogenesis, decreasing cost and burden of male contraception trials and increasing practicality of the method.

Clinical trial registration number

NCT: 03452111.

Context

Night-shift work causes circadian misalignment, predicts the development of metabolic diseases, and complicates the interpretation of hormone measurements.

Objective

To investigate endogenous circadian rhythms, dissociated from behavioral and environmental confounds, in adrenal and gonadal steroids after simulated shift work.

Methods

Fourteen healthy adults (ages 25.8 ± 3.2 years) were randomized to 3 days of night or day (control) shift work followed by a constant routine protocol designed to experimentally unveil rhythms driven endogenously by the central circadian pacemaker. Blood was sampled every 3 hours for 24 hours during the constant routine to concurrently obtain 16 Δ4 steroid profiles by mass spectrometry. Cosinor analyses of these profiles provided mesor (mean abundance), amplitude (oscillation magnitude), and acrophase (peak timing).

Results

Night-shift work marginally increased cortisol by 1 μg/dL (P = 0.039), and inactive/weak derivatives cortisone (P = 0.003) and 18-hydroxycortisol (P < 0.001), but did not alter the mesor of potent androgens testosterone and 11-ketotestosterone. Adrenal-derived steroids, including 11-ketotestosterone (P < 0.01), showed robust circadian rhythmicity after either day- or night-shift work. In contrast, testosterone and progesterone showed no circadian pattern after both shift work conditions. Night-shift work did not alter the amplitude or acrophase of any of the steroid profiles.

Conclusion

Experimental circadian misalignment had minimal effects on steroidogenesis. Adrenal steroids, but not gonadal hormones, showed endogenous circadian regulation robust to prior shift schedule. This dichotomy may predispose night-shift workers to metabolic ill health. Furthermore, adrenal steroids, including cortisol and the main adrenal androgen 11-ketostosterone, should always be evaluated during the biological morning whereas assessment of gonadal steroids, particularly testosterone, is dependent on the shift-work schedule.

Objective

To determine men's satisfaction with and acceptability of a once-daily, oral regimen of dimethandrolone undecanoate (DMAU) versus placebo when used for 28 days.

Study design

After a Phase I double-blind, randomized, placebo-controlled, dose-escalating trial of oral DMAU for 28-days, 57 healthy male volunteers completed a survey assessing their experience and satisfaction with the regimen. In the trial, participants were randomized to receive up to 4 DMAU capsules daily versus placebo and instructed to ingest them within 30 min of consuming a high fat meal. Pharmacokinetic and pharmacodynamic profiles were performed, followed by a 6-week recovery phase. Participants were counseled that they could not rely on the drug for contraception.

Results

Fifty-seven participants were offered acceptability surveys (39 DMAU, 18 placebo). Most respondents, 80% (45/56), reported satisfaction with the method; 77% (44/57) would recommend it. 54% (31/57), reported that, if available, they would use the method as their primary contraceptive. More respondents reported satisfaction with active DMAU than placebo (87% vs. 67%; p = 0.05). Most respondents, 91% (52/57), reported no difficulty with having to take up to 4 pills within 30 min of ingesting a high-fat meal.

Conclusion

Most participants reported that the study method, daily oral DMAU or placebo, was satisfactory and acceptable. Having to take the drug after a high-fat meal did not detract from acceptability.

Implications

Most participants in a 4-week trial of daily DMAU capsules would recommend and use the method. High satisfaction among DMAU and placebo groups affirms acceptability of a daily male contraceptive pill, warranting further study of oral DMAU.