Acceptability of a combination testosterone gel and depomedroxyprogesterone acetate male contraceptive regimen

Real-life users of hormonal or thermal male contraception: An analysis of female partners' motivation, experience, and satisfaction

BACKGROUND

Two male contraceptive methods that inhibit spermatogenesis currently exist: thermal male contraception and hormonal male contraception. Only five studies have been conducted on the acceptability of these methods among men; among women, only the hypothetical acceptability of such a male contraceptive approach as the sole contraception method used by a couple has been evaluated.

OBJECTIVES

To evaluate the motivation, experience, and satisfaction of female partners in couples using hormonal male contraception or thermal male contraception as the sole contraception.

MATERIALS AND METHODS

In this cross-sectional study, 123 male users of hormonal male contraception or thermal male contraception as the couple's sole contraception method were asked to invite their female partner to participate in an anonymous online survey. The questionnaire included 95 questions exploring population characteristics, contraceptive and pregnancy history, motivations for choosing hormonal male contraception or thermal male contraception, the experience of the women in the successive phase of use, relationships with their partner, and satisfaction with the contraception method.

RESULTS

The response rate among participating women was 69% (59/86). The two main reasons for choosing male contraceptive were the desire to share the contraception role in the couple (65%) and the desire of the man to take charge of the contraception (61%). The sexual satisfaction score increased significantly between the contraceptive methods used before hormonal male contraception or thermal male contraception and the phase of contraceptive use (p < 0.01). The overall satisfaction level with thermal male contraception or hormonal male contraception was rated at 3.7 ± 0.6 out of 4. Women mostly recommended hormonal male contraception or thermal male contraception because of the share of contraceptive responsibility and mental load (n = 23/54, 43%).

DISCUSSION

This population of women seemed to have struggled to find a contraceptive method that suited them, but most took advantage of thermal male contraception or hormonal male contraception and trusted their male partner to take charge of contraception use.

CONCLUSION

The positive evaluation from women in partnerships using thermal male contraception and hormonal male contraception should encourage the development of these methods.

'That just sounds bizarre': factors affecting heterosexual college students' perceptions of new sperm-targeting contraceptives

Contraceptive responsibility has historically fallen on women in the context of heterosexual relationships, often resulting in a perceived burden on their emotional and reproductive health. We conducted in-depth, individual interviews with women and men in college to investigate factors influencing the choices they make regarding contraceptive use and more specifically their perceptions and willingness to try new sperm-targeting contraceptives. Thematic analysis revealed factors at a societal, interpersonal, and individual level affecting participants' perceptions and imagined decisions. Societally, a perceived gendered divide continues to exist placing primary responsibility for contraceptive use on women. Interpersonally, the context of a relationship increased partners' feelings of empathy and willingness to try alternative contraceptive methods; and individually participants remained concerned about their own sexual and reproductive safety. Findings indicate that societal level norms need to be shifted towards the acceptability of sperm-targeting contraceptives or other versions of contraceptives that act on male bodies, in addition to a greater focus on their development. It is proposed that this would help to ease the continued undue burden placed on women for reproductive health.

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.

Thermal male contraception: A study of users' motivation, experience, and satisfaction

PURPOSE

The aim of this study is to evaluate the motivations, experience, and acceptability of thermal male contraception (TMC) in male partners of couples requesting the use of TMC as the only couple contraceptive.

MATERIALS AND METHODS

To the 72 men of couples seeking male contraception and using TMC between 2011 and 2019, we suggested an anonymous online survey (93 questions) exploring population characteristics, contraceptive histories, motivations for choosing TMC, patient experience at the successive phases of use, relations with partner and environment, and satisfaction with this method.

RESULTS

Sixty-seven men agreed to participate (93% response rate); 63 responses were complete and were analyzed (94% participation rate). The main motivations for choosing TMC were "not using hormones" (n = 59/63, 94%) and using a method regarded as "natural" (n = 49/63, 78%). Most of the men surveyed (68%) adopted the method in less than 2 weeks. During the contraception use phase (n = 59 men), they described significantly improved sexual satisfaction, compared to that experienced with their previous contraceptive methods, and they reported high confidence (100% rather/totally confident partner) and support (88% rather/totally supporting partner) from their partner. Most men (n = 35/59, 59%) also reported improved self-esteem. The main negative point was discomfort, reported by 24% of the men. The overall satisfaction score of using this method was 3.78 ± 0.46/4, and 100% of the men reported that they would recommend the method to other men.

DISCUSSION AND CONCLUSION

Men using TMC successfully assumed the responsibility for and performed a daily task to provide couple contraception. This positive evaluation, together with the already published contraceptive efficacy and reversibility of TMC, should encourage the development of this method.

Hormonal Male Contraception: Getting to Market

Rates of unplanned pregnancies are high and stagnant globally, burdening women, families and the environment. Local limitations placed upon contraceptive access and abortion services exacerbate global disparities for women. Despite survey data suggesting men and their partners are eager for expanded male contraceptive options, efforts to develop such agents have been stymied by a paucity of monetary investment. Modern male hormonal contraception, like female hormonal methods, relies upon exogenous progestins to suppress the hypothalamic-pituitary-gonadal axis, in turn suppressing testicular testosterone production and sperm maturation. Addition of an androgen augments gonadotropin suppression, more effectively suppressing spermatogenesis in men, and provides androgenic support for male physiology. Previous contraceptive efficacy studies in couples have shown that hormonal male methods are effective and reversible. Recent efforts have been directed at addressing potential user and regulatory concerns by utilizing novel steroids and varied routes of hormone delivery. Provision of effective contraceptive options for men and women is an urgent public health need. Recognizing and addressing the gaps in our contraceptive options and engaging men in family planning will help reduce rates of unplanned pregnancies in the coming decades.

Will Men Use Novel Male Contraceptive Methods and Will Women Trust Them? A Systematic Review

Novel male contraceptives have been in development for almost as long as female methods, yet there are no products available on the market. Hormonal approaches tested clinically to date include the use of oral, injectable, implant and transdermal methods. The study of attitudes toward male contraception has been inconsistent and there have been no systematic reviews drawing these data together. We conducted a systematic review of the available evidence for male and female acceptability of novel male contraception. We identified 32 studies and present a narrative synthesis of quantitative data and a thematic synthesis of qualitative data. In novel drug trials, the proportion of male participants willing to use a male contraceptive ranged from 34.0% to as high as 82.3%. In studies regarding hypothetical drugs, male willingness to use ranged from 13.6% to 83.0%. High proportions of women (42.8%-94.0%) reported willingness to use a novel male method in both hypothetical studies and actual drug trials. In qualitative studies, both men and women expressed the desire to share responsibility for contraception. There is consistent interest among both men and women in novel male contraceptive methods and willingness to use them. The systematic review was registered with PROSPERO: CRD42020173281.

What About Methods for Men? A Qualitative Analysis of Attitudes Toward Male Contraception in Burkina Faso and Uganda

CONTEXT

Male contraceptive options are limited; however, product development efforts tend to focus on female methods. Research on attitudes toward methods for men-particularly in regions of low contraceptive prevalence, such as Sub-Saharan Africa-could inform the development of new male methods.

METHODS

Qualitative data were taken from focus group discussions with 80 men aged 23-67 and 398 women aged 15-50 conducted in Burkina Faso and Uganda in 2016. Transcripts were analyzed thematically to explore support among men and women for male contraceptive methods, and to extract suggestions about ideal method characteristics.

RESULTS

Male and female participants in both countries expressed support for new male contraceptive options; more positive attitudes were expressed in Uganda than in Burkina Faso. Participants of both sexes recognized that male methods could reduce the family planning burden on women and offer men greater control over their fertility; however, some had concerns about side effects and thought that men would not use contraceptives. Relationship characteristics, such as polygamous unions, were cited as possible challenges. In both countries, various delivery methods (e.g., creams or jellies, injections and implants) and durations (from short-acting to permanent) were proposed.

CONCLUSIONS

The acceptability of new male methods among most participants in the two countries indicates a potential demand for male contraceptives. Options should include a variety of method characteristics to maximize choice, engage men, and support men and women's contraceptive needs.

Acceptability of oral dimethandrolone undecanoate in a 28-day placebo-controlled trial of a hormonal male contraceptive prototype

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.

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.

Combined nestorone-testosterone gel suppresses serum gonadotropins to concentrations associated with effective hormonal contraception in men

BACKGROUND

Novel male-based contraceptives are needed to broaden family planning choices. A progestin, Nestorone^® (Nes) gel, plus a testosterone (T) gel suppresses sperm concentrations to levels associated with effective contraception in normal men. However, administration of two gels on different parts of the body daily is impractical.

OBJECTIVE

Compare the effectiveness of daily application of a single, combined 8.3 mg Nes-62.5 mg T gel (Nes-T) vs. 62.7 mg T gel to suppress serum FSH and LH concentrations to ≤1.0 IU/L (a threshold associated with suppression of sperm concentrations to ≤1 million and effective contraception) and to compare the pharmacokinetics of serum Nes and T concentrations between the gel groups.

DESIGN

We conducted a 28-day, double-blind, controlled trial of 44 healthy men randomized to daily Nes-T or T gel with measurement of hormones at baseline, treatment, and recovery and during 24-h pharmacokinetic studies on days 1 and 28 of treatment.

RESULTS

Of the subjects who met pre-defined inclusion criteria, 84% of the Nes-T group suppressed serum gonadotropin concentrations to ≤1.0 IU/L at days 21-28 vs. 16.7% in the T group (p < 0.001). On day 1, Nes concentrations rose significantly above baseline by 2 h and continued to rise up to 24 h after Nes-T gel application. Nes concentrations were not detectable in the T group. Serum total T concentrations rose and were significantly higher in the T gel group compared to the Nes-T group at 24 h on day 1 and days 11, 14, and 21 (p < 0.01). There were no serious adverse events in either group. About 80% of the subjects reported satisfaction with both gels.

CONCLUSION

Daily Nes-T gel effectively and safely suppresses serum gonadotropins and is acceptable to most men. It should be studied further in efficacy trials of hormonal male contraception.

Modeling the impact of novel male contraceptive methods on reductions in unintended pregnancies in Nigeria, South Africa, and the United States

OBJECTIVE

We modeled the potential impact of novel male contraceptive methods on averting unintended pregnancies in the United States, South Africa, and Nigeria.

STUDY DESIGN

We used an established methodology for calculating the number of couple-years of protection provided by a given contraceptive method mix. We compared a "current scenario" (reflecting current use of existing methods in each country) against "future scenarios," (reflecting whether a male oral pill or a reversible vas occlusion was introduced) in order to estimate the impact on unintended pregnancies averted. Where possible, we based our assumptions on acceptability data from studies on uptake of novel male contraceptive methods.

RESULTS

Assuming that only 10% of interested men would take up a novel male method and that users would comprise both switchers (from existing methods) and brand-new users of contraception, the model estimated that introducing the male pill or reversible vas occlusion would decrease unintended pregnancies by 3.5% to 5.2% in the United States, by 3.2% to 5% in South Africa, and by 30.4% to 38% in Nigeria. Alternative model scenarios are presented assuming uptake as high as 15% and as low as 5% in each location. Model results were sensitive to assumptions regarding novel method uptake and proportion of switchers vs. new users.

CONCLUSION

Even under conservative assumptions, the introduction of a male pill or temporary vas occlusion could meaningfully contribute to averting unintended pregnancies in a variety of contexts, especially in settings where current use of contraception is low.

IMPLICATIONS

Novel male contraceptives could play a meaningful role in averting unintended pregnancies in a variety of contexts. The potential impact is especially great in settings where current use of contraception is low and if novel methods can attract new contraceptive users.

Male hormonal contraception: hope and promise

Family planning is a shared responsibility, but available male-directed contraceptive methods are either not easily reversible (vasectomy) or not sufficiently effective (condom). However, roughly 20% of couples using a contraceptive method worldwide, and up to 80% in some countries, still choose a male-directed method. Male hormonal contraception is highly effective, with perfect use failure rates of 0·6% (95% CI 0·3-1·1) if sperm concentrations of less than 1 million per mL are maintained. After cessation of male hormonal contraception, sperm output fully recovers in a predictable manner, resulting in pregnancies and livebirths. Spontaneous miscarriage and fetal malformation rates after recovery of sperm output overlap those in the general population. Short-term adverse events-acne, night sweats, increased weight, and altered mood and libido-are recognised, but are generally mild. Further optimisation of specific androgen-progestin regimens and phase 3 studies of lead combinations are still needed to successfully develop an approved male hormonal contraceptive and to identify long-term side-effects.

The current state of male hormonal contraception

World population continues to grow at an unprecedented rate, doubling in a mere 50years to surpass the 7-billion milestone in 2011. This steep population growth exerts enormous pressure on the global environment. Despite the availability of numerous contraceptive choices for women, approximately half of all pregnancies are unintended and at least half of those are unwanted. Such statistics suggest that there is still a gap in contraceptive options for couples, particularly effective reversible contraceptives for men, who have few contraceptive choices. Male hormonal contraception has been an active area of research for almost 50years. The fundamental concept involves the use of exogenous hormones to suppress endogenous production of gonadotropins, testosterone, and downstream spermatogenesis. Testosterone-alone regimens are effective in many men but high dosing requirements and sub-optimal gonadotropin suppression in 10-30% of men limit their use. A number of novel combinations of testosterone and progestins have been shown to be more efficacious but still require further refinement in delivery systems and a clearer understanding of the potential short- and long-term side effects. Recently, synthetic androgens with both androgenic and progestogenic activity have been developed. These agents have the potential to be single-agent male hormonal contraceptives. Early studies of these compounds are encouraging and there is reason for optimism that these may provide safe, reversible, and reliable contraception for men in the near future.

Male Hormonal Contraception: Where Are We Now?

Hormonal male contraception clinical trials began in the 1970s. The method is based on the use of exogenous testosterone alone or in combination with a progestin to suppress the endogenous production of testosterone and spermatogenesis. Studies using testosterone alone showed that the method was very effective with few adverse effects. Addition of a progestin increases the rate and extent of suppression of spermatogenesis. Common adverse effects include acne, injection site pain, mood change including depression, and changes in libido that are usually mild and rarely lead to discontinuation. Current development includes long-acting injectables and transdermal gels and novel androgens that may have both androgenic and progestational activities. Surveys showed that over 50 % of men will accept a new male method and female partners will trust their partner to take oral “male pills.” Partnership between government, nongovernment agencies, academia, and industry may generate adequate interest and collaboration to develop and market the first male hormonal contraception.

Social constructions of the male contraception pill: When are we going to break the vicious circle?

Social constructions of men towards the availability of a male hormonal contraceptive, the 'male pill', were explored. A qualitative approach applying semi-structured interviews and scenarios with 22 men (mean age 35 years) from the North East of England revealed two core constructs and six sub-constructs using a Thematic-Construct Analysis in line with the method of Toerien and Wilkinson and Clarke and Kitzinger. Verbal accounts were inductively used to balance the deductively created two core constructs 'Constructing the male pill norm: dominant system of sensemaking' and 'Living by the male pill norm' to represent a normative framework within a changing ideology of shared responsibility in contraceptive choice. Constructing the male pill norm was divided into two sub-constructs: 'Male pill: we are going to join the women and become responsible - too!' and 'Male pill: you look so girly - what are they going to think of me?' The 'Living by the male pill norm' was further divided into four sub-constructs 'Male pill - thank you for giving me promises not to have to become a dad as yet!'; 'Male pill: thank you for the idea of fun - sorry about my morals!'; 'Male pill: in stable relations - yes, I would have you now - sorry, I am too late!' and 'Male pill, we love you - but we are too anxious - we are not ready as yet!' From this male discourse, it is clear that discussions over the male pill follow the line of a vicious circle. In order to establish long-term side effects, Phase IV studies are necessary, and these cannot commence without the male hormonal contraception being a marketable product. So, unless this circle gets broken by some brave men, the male pill will remain a virtual rotating idea for a long time.

Male contraception

Clear evidence shows that many men and women would welcome new male methods of contraception, but none have become available. The hormonal approach is based on suppression of gonadotropins and thus of testicular function and spermatogenesis, and has been investigated for several decades. This approach can achieve sufficient suppression of spermatogenesis for effective contraception in most men, but not all; the basis for these men responding insufficiently is unclear. Alternatively, the non-hormonal approach is based on identifying specific processes in sperm development, maturation and function. A range of targets has been identified in animal models, and targeted effectively. This approach, however, remains in the pre-clinical domain at present. There are, therefore, grounds for considering that safe, effective and reversible methods of contraception for men can be developed.

Acceptability of a transdermal gel-based male hormonal contraceptive in a randomized controlled trial

OBJECTIVE

Fifty percent of pregnancies in the United States are unintended despite numerous contraceptive methods available to women. The only male contraceptive methods, vasectomy and condoms, are used by 10% and 16% of couples, respectively. Prior studies have shown efficacy of male hormonal contraceptives in development, but few have evaluated patient acceptability and potential use if commercially available. The objective of this study is to determine if a transdermal gel-based male hormonal contraceptive regimen, containing testosterone and Nestorone® gels, would be acceptable to study participants as a primary contraceptive method.

STUDY DESIGN

As part of a three-arm, 6-month, double-blind, randomized controlled trial of testosterone and nestorone gels at two academic medical centers, subjects completed a questionnaire to assess the acceptability of the regimen. Of the 99 men randomized, 79 provided data for analysis.

RESULTS

Overall, 56% (44/79) of men were satisfied or extremely satisfied with this gel-based method of contraception, and 51% (40/79) reported that they would recommend this method to others. One third of subjects (26/79) reported that they would use this as their primary method of contraception if it were commercially available today. However, men with concerns about sexually transmitted disease were significantly less satisfied than men without such concerns (p=0.03).

CONCLUSIONS

A majority of the men who volunteered to participate in this trial of an experimental male hormonal contraceptive were satisfied with this transdermal male hormonal contraceptive. If commercially available, a combination of topical nesterone and testosterone gels could provide a reversible, effective method of contraception that is appealing to men.

IMPLICATIONS

A substantial portion of men report they would use this transdermal male contraceptive regimen if commercially available. This method would provide a novel, reversible method of contraception for men, whose current choices are limited to condoms and vasectomy.

Male contraception: history and development

Although the twentieth century has seen great strides in the development of female contraception, not a single new agent has been introduced as an approved method for common use for male contraception. Condoms (considered uncomfortable by some) and vasectomy (a permanent invasive procedure) are the only options provided to men, leaving an undue burden on women to bear contraceptive responsibility. Significant developments have, however, been made with regard to hormonal and nonhormonal contraception, and minor, reversible, procedural contraception. This article reviews the currently available, soon to be available, and theoretically possible methods of male contraception.

Demand for male contraception

The biological basis for male contraception was established decades ago, but despite promising breakthroughs and the financial burden men increasingly bear due to better enforcement of child support policies, no viable alternative to the condom has been brought to market. Men who wish to control their fertility must rely on female compliance with contraceptives, barrier methods, vasectomy or abstinence. Over the last 10 years, the pharmaceutical industry has abandoned most of its investment in the field, leaving only nonprofit organisations and public entities pursuing male contraception. Leading explanations are uncertain forecasts of market demand pitted against the need for critical investments to demonstrate the safety of existing candidate products. This paper explores the developments and challenges in male contraception research. We produce preliminary estimates of potential market size for a safe and effective male contraceptive based on available data to estimate the potential market for a novel male method.

Attitudes towards the male contraceptive pill: psychosocial and cultural explanations for delaying a marketable product

Even though years of research on the male contraceptive pill have been conducted, a marketable product is still absent from the arsenal of male and female products of contraception. In this paper, the following psychosocial and cultural factors have been elicited from the literature in order to reveal explanations for this delay: acceptability, trust, fear of side-effects, perceptions of contraceptive responsibility and fear of losing connotations of masculinity. Regardless of cultural variation, overall there seems to be a positive attitude towards the acceptability of male contraceptive for both males and females, especially males in stable relationships. Some indication shows that the media have played an important role in distorting the results of research regarding male and female trust. Ongoing and future researches into several projects on psychosocial and cultural factors are described.

Steroid hormones for contraception in men

BACKGROUND

Male hormonal contraception has been an elusive goal. Administration of sex steroids to men can shut off sperm production through effects on the pituitary and hypothalamus. However, this approach also decreases production of testosterone, so 'add-back' therapy is needed.

OBJECTIVES

To summarize all randomized controlled trials (RCTs) of male hormonal contraception.

SEARCH METHODS

In January and February 2012, we searched the computerized databases CENTRAL, MEDLINE, POPLINE, and LILACS. We also searched for recent trials in ClinicalTrials.gov and ICTRP. Previous searches included EMBASE. We wrote to authors of identified trials to seek additional unpublished or published trials.

SELECTION CRITERIA

We included all RCTs that compared a steroid hormone with another contraceptive. We excluded non-steroidal male contraceptives, such as gossypol. We included both placebo and active-regimen control groups.

DATA COLLECTION AND ANALYSIS

The primary outcome measure was the absence of spermatozoa on semen examination, often called azoospermia. Data were insufficient to examine pregnancy rates and side effects.

MAIN RESULTS

We found 33 trials that met our inclusion criteria. The proportion of men who reportedly achieved azoospermia or had no detectable sperm varied widely. A few important differences emerged. 1) Levonorgestrel implants (160 μg daily) combined with injectable testosterone enanthate (TE) were more effective than levonorgestrel 125 µg daily combined with testosterone patches. 2) Levonorgestrel 500 μg daily improved the effectiveness of TE 100 mg injected weekly. 3) Levonorgestrel 250 μg daily improved the effectiveness of testosterone undecanoate (TU) 1000 mg injection plus TU 500 mg injected at 6 and 12 weeks. 4) Desogestrel 150 μg was less effective than desogestrel 300 μg (with testosterone pellets). 5) TU 500 mg was less likely to produce azoospermia than TU 1000 mg (with levonorgestrel implants). 6) Norethisterone enanthate 200 mg with TU 1000 mg led to more azoospermia when given every 8 weeks versus 12 weeks. 7) Four implants of 7-alpha-methyl-19-nortestosterone (MENT) were more effective than two MENT implants. We did not conduct any meta-analysis due to intervention differences.Several trials showed promising efficacy in percentages with azoospermia. Three examined desogestrel and testosterone preparations or etonogestrel and testosterone, and two examined levonorgestrel and testosterone.

AUTHORS' CONCLUSIONS

No male hormonal contraceptive is ready for clinical use. Most trials were small exploratory studies. Their power to detect important differences was limited and their results imprecise. In addition, assessment of azoospermia can vary by sensitivity of the method used. Future trials need more attention to the methodological requirements for RCTs. More trials with adequate power would also be helpful.

Recent methodological advances in male hormonal contraception

Landmark WHO-sponsored trials showed decades ago that male hormonal contraception (MHC) is an effective male-directed contraceptive approach. Considerable progress has been made particularly in the last 5 years, establishing for the first time the reversibility of MHC and its short-term safety. Methodological advances in recent years include the pooling of information and individual-level integrated analysis; the first-time use of centralized semen analysis and fluorescence to detect low sperm concentrations; the establishment of sperm quality reference ranges in fertile men; the measurement of blood steroid concentrations by gas chromatography/mass spectrometry; and the inclusion of placebo groups to delineate clearly possible adverse effects of androgens and progestins in men. We report integrated analyses of factors that are important in predicting suppression and recovery of spermatogenesis after MHC clinical trials for the past 15 years. These are the best data available and will provide guidance and reassurance for the larger-scale Phase III specific regimen efficacy studies that will be required to bring MHC to the population (market).

Pharmacologic development of male hormonal contraceptive agents

The world population continues to increase dramatically despite the existence of contraceptive technology. The use of male hormonal contraception may help in preventing un intended pregnancies and managing future population growth. Male hormonal contraception relies on the administration of exogenous hormones to suppress spermatogenesis. Clinical trials have tested several regimens using testosterone, alone or in combination with a progestin. These regimens were shown to be >90% effective in preventing conception and were not associated with serious adverse events.

Acceptability of contraception for men: a review

Methods of contraception for use by men include condoms, withdrawal and vasectomy. Prevalence of use of a method and continuation rates are indirect measures of acceptability. Worldwide, none of these "male methods" accounts for more than 7% of contraceptive use although uptake varies considerably between countries. Acceptability can be assessed directly by asking about intended (hypothetical) use and assessing satisfaction during/after use. Since they have been around for a very long time, there are very few data of this nature on condoms (as contraceptives rather than for prevention of infection), withdrawal or vasectomy. There are direct data on the acceptability of hormonal methods for men but from relatively small clinical trials which undoubtedly do not represent the real world. Surveys undertaken among the male general public demonstrate that, whatever the setting, at least 25% of men - and in most countries substantially more - would consider using hormonal contraception. Although probably an overestimate of the number of potential users when such a method becomes available, it would appear that hormonal contraceptives for men may have an important place on the contraceptive menu. Despite commonly expressed views to the contrary, most women would trust their male partner to use a hormonal method.

Advances in male contraception

Despite significant advances in contraceptive options for women over the last 50 yr, world population continues to grow rapidly. Scientists and activists alike point to the devastating environmental impacts that population pressures have caused, including global warming from the developed world and hunger and disease in less developed areas. Moreover, almost half of all pregnancies are still unwanted or unplanned. Clearly, there is a need for expanded, reversible, contraceptive options. Multicultural surveys demonstrate the willingness of men to participate in contraception and their female partners to trust them to do so. Notwithstanding their paucity of options, male methods including vasectomy and condoms account for almost one third of contraceptive use in the United States and other countries. Recent international clinical research efforts have demonstrated high efficacy rates (90-95%) for hormonally based male contraceptives. Current barriers to expanded use include limited delivery methods and perceived regulatory obstacles, which stymie introduction to the marketplace. However, advances in oral and injectable androgen delivery are cause for optimism that these hurdles may be overcome. Nonhormonal methods, such as compounds that target sperm motility, are attractive in their theoretical promise of specificity for the reproductive tract. Gene and protein array technologies continue to identify potential targets for this approach. Such nonhormonal agents will likely reach clinical trials in the near future. Great strides have been made in understanding male reproductive physiology; the combined efforts of scientists, clinicians, industry and governmental funding agencies could make an effective, reversible, male contraceptive an option for family planning over the next decade.

Progress and prospects in male hormonal contraception

PURPOSE OF REVIEW

Testosterone functions as a contraceptive by suppressing the secretion of luteinizing hormone and follicle-stimulating hormone from the pituitary. Low concentrations of these hormones deprive the testes of the signals required for spermatogenesis and results in markedly decreased sperm concentrations and effective contraception in a majority of men. Male hormonal contraception is well tolerated and acceptable to most men. Unfortunately, testosterone-alone regimens fail to completely suppress spermatogenesis in all men, meaning that in some the potential for fertility remains.

RECENT FINDINGS

Because of this, novel combinations of testosterone and progestins, which synergistically suppress gonadotropins, have been studied. Two recently published testosterone/progestin trials are particularly noteworthy. In the first, a long-acting injectable testosterone ester, testosterone decanoate, was combined with etonogestrel implants and resulted in 80-90% of subjects achieving a fewer than 1 million sperm per milliliter. In the second, a daily testosterone gel was combined with 3-monthly injections of depot medroxyprogesterone acetate producing similar results.

SUMMARY

Testosterone-based hormone combinations are able to reversibly suppress human spermatogenesis; however, a uniformly effective regimen has remained elusive. Nevertheless, improvements, such as the use of injectable testosterone undecanoate, may lead to a safe, reversible and effective male contraceptive.

Steroid hormones for contraception in men

BACKGROUND

Male hormonal contraception has been an elusive goal. Administration of sex steroids to men can shut off sperm production through effects on the pituitary and hypothalamus. However, this approach also decreases production of testosterone, so 'add-back' therapy is needed.

OBJECTIVES

To summarize all randomized controlled trials of male hormonal contraception.

SEARCH STRATEGY

We searched the computerized databases CENTRAL, MEDLINE, EMBASE, POPLINE, and LILACS (each from inception to March 2006) for randomized controlled trials of hormonal contraception in men. We wrote to authors of identified trials to seek unpublished or published trials that we might have missed.

SELECTION CRITERIA

We included all randomized controlled trials in any language that compared a steroid hormone with another contraceptive. We excluded non-steroidal male contraceptives, such as gossypol. We included both placebo and active-regimen control groups. All trials identified included only healthy men with normal semen analyses.

DATA COLLECTION AND ANALYSIS

Azoospermia (absence of spermatozoa on semen examination) was the primary outcome measure. Data were insufficient to examine pregnancy rates and side effects.

MAIN RESULTS

We found 30 trials that met our inclusion criteria. The proportion of men who achieved azoospermia varied widely in reports to date. A few important differences emerged from these trials: levonorgestrel implants combined with injectable testosterone enanthate (TE) were more effective than levonorgestrel 125 microg daily combined with testosterone patches; levonorgestrel 500 mug daily improved the effectiveness of TE 100 mg injected weekly; desogestrel 150 mug was less effective than desogestrel 300 mug (with testosterone pellets); testosterone undecanoate (TU) 500 mg was less likely to produce azoospermia than TU 1000 mg (with levonorgestrel implants); norethisterone enanthate 200 mg with TU 1000 mg led to more azoospermia when given every 8 weeks versus 12 weeks; four implants of 7-alpha-methyl-19-nortestosterone (MENT) were more effective than two MENT implants. Several trials showed promising efficacy in terms of percentages with azoospermia. Three examined desogestrel and testosterone preparations or etonogestrel (metabolite of desogestrel) and testosterone, and two examined levonorgestrel and testosterone.

AUTHORS' CONCLUSIONS

No male hormonal contraceptive is ready for clinical use. Most trials were small exploratory studies. As a result, their power to detect important differences was limited and their results imprecise. In addition, the definition of oligozoospermia has been imprecise or inconsistent. To avoid bias, future trials need more attention to the methodological requirements for randomized controlled trials. More trials with adequate power would also be helpful.