Two landmark contraceptive efficacy studies of testosterone induced azoospermia and severe oligozoospermia conducted by WHO (World Health Organization) in 1990s showed conclusively that when spermatogenesis is severely suppressed by exogenous intramuscular administration of testosterone in healthy men, contraceptive efficacy comparable to hormonal contraceptive methods for women can be achieved. Since then three contraceptive efficacy studies have been conducted that confirmed the effectiveness of hormonal male contraception. These have been supported by the Chinese Government, WHO, and other non-government organizations. However, it should be noted that the majority of men participating in these more recent contraceptive efficacy studies originated from China.
Ethnicity is an important consideration for the development of a universally applicable male hormonal contraceptive that can be utilized throughout both the developed and developing world. Potential ethnic influences include acceptability of the method by men and their partners; ease of use of certain regimens and delivery methods (e.g. injections versus other pills); rapidity or extent of suppression of sperm output; effectiveness of suppression of spermatogenesis by different hormonal regimens; and reversibility of spermatogenesis after cessation of male hormonal contraception. Whether optimization of treatment regimens or dosages of the steroid hormones can overcome these ethnic differences is unclear. In this review, they have elected to focus on the influence of ethnicity on male contraceptive development and highlight the leadership role of East Asian investigators and the supportive government and non-government organizations in accelerating progress of this field. For the purpose of this review, East Asian men refer to men mainly from China and Indonesia and Caucasian men refer to white men with European ancestry. In addition, they use efficacy for contraceptive efficacy and effectiveness to denote adequate suppression of sperm concentration to levels that are compatible with contraceptive efficacy.
Ilani N, Liu PY, Swerdloff RS, Wang C. Does ethnicity matter in male hormonal contraceptive efficacy? Asian J Androl. Does ethnicity matter in male hormonal contracepti... [Asian J Androl. 2011] - PubMed result
The development of male hormonal contraception has progressed significantly during the last three decades. The ultimate goal is to produce an effective, safe and reversible male method of contraception that are within reach of and can be used by all men globally. This review aims to outline the recent developments in male hormonal contraception with special emphasis on how ethnicity influences acceptability, extent of sperm suppression, and rate of recovery of spermatogenesis. Baseline differences in testicular histomorphology and testosterone metabolism between East Asian and Caucasian men have been reported, but whether this contributes significantly to varying degrees of sperm suppression in response to exogenous testosterone therapy is less known. Testosterone alone male hormonal contraceptive regimens are effective and applicable for East Asian men, and less so for Caucasians. Combinations of progestins with androgens are sufficient to optimize effectiveness of suppression and applicability to all ethnicities. New compounds such as steroidal or non-steroidal selective androgen receptor modulators with dual androgenic and progestational activities are potential compounds for further development as male hormonal contraceptive methods. At the present time, combined androgen and progestin contraceptive regimens appear to be effective, safe, reversible and convenient to use for all men with ethnic, cultural and environmental differences. Further refinements on the hormonal agent, methods of delivery, and dose optimization of the androgen relative to the progestin are necessary. This goal mandates further investment and large clinical trials in multiethnic populations to better define safety and efficacy.
Ethnicity is an important consideration for the development of a universally applicable male hormonal contraceptive that can be utilized throughout both the developed and developing world. Potential ethnic influences include acceptability of the method by men and their partners; ease of use of certain regimens and delivery methods (e.g. injections versus other pills); rapidity or extent of suppression of sperm output; effectiveness of suppression of spermatogenesis by different hormonal regimens; and reversibility of spermatogenesis after cessation of male hormonal contraception. Whether optimization of treatment regimens or dosages of the steroid hormones can overcome these ethnic differences is unclear. In this review, they have elected to focus on the influence of ethnicity on male contraceptive development and highlight the leadership role of East Asian investigators and the supportive government and non-government organizations in accelerating progress of this field. For the purpose of this review, East Asian men refer to men mainly from China and Indonesia and Caucasian men refer to white men with European ancestry. In addition, they use efficacy for contraceptive efficacy and effectiveness to denote adequate suppression of sperm concentration to levels that are compatible with contraceptive efficacy.
Ilani N, Liu PY, Swerdloff RS, Wang C. Does ethnicity matter in male hormonal contraceptive efficacy? Asian J Androl. Does ethnicity matter in male hormonal contracepti... [Asian J Androl. 2011] - PubMed result
The development of male hormonal contraception has progressed significantly during the last three decades. The ultimate goal is to produce an effective, safe and reversible male method of contraception that are within reach of and can be used by all men globally. This review aims to outline the recent developments in male hormonal contraception with special emphasis on how ethnicity influences acceptability, extent of sperm suppression, and rate of recovery of spermatogenesis. Baseline differences in testicular histomorphology and testosterone metabolism between East Asian and Caucasian men have been reported, but whether this contributes significantly to varying degrees of sperm suppression in response to exogenous testosterone therapy is less known. Testosterone alone male hormonal contraceptive regimens are effective and applicable for East Asian men, and less so for Caucasians. Combinations of progestins with androgens are sufficient to optimize effectiveness of suppression and applicability to all ethnicities. New compounds such as steroidal or non-steroidal selective androgen receptor modulators with dual androgenic and progestational activities are potential compounds for further development as male hormonal contraceptive methods. At the present time, combined androgen and progestin contraceptive regimens appear to be effective, safe, reversible and convenient to use for all men with ethnic, cultural and environmental differences. Further refinements on the hormonal agent, methods of delivery, and dose optimization of the androgen relative to the progestin are necessary. This goal mandates further investment and large clinical trials in multiethnic populations to better define safety and efficacy.