Male contraception: A realistic option?

Abstract

This review illustrates the principle of hormonal male contraception and gives an overview of current trials aiming at the development of a marketable hormonal contraceptive for men. The principle of male hormonal contraception is based on strong suppression of gonadotropins in order to arrest spermatogenesis at the spermatogonial stem cell level, thus leading to azoospermia or severe oligozoospermia. Until now, it has not been possible to interrupt spermatogenesis effectively without simultaneously inhibiting the production of androgens by Leydig cells, resulting in a deficiency of extra-testicular androgens. Therefore, testosterone needs to be replaced. By administering exogenous testosterone alone azoospermia can be reached in East Asians, whereas azoospermia is only achieved in two-thirds of Caucasian volunteers so that in these men an additional agent is required. Currently injectable testosterone combined with gestagens or administered as implants are being tested for possible licensing. Although scrotal and non-scrotal testosterone patches, orally administered testosterone undecanoate and testosterone gels are generally well tolerated and provide stable testosterone levels in the normal range, their use showed generally disappointing efficacy due to insufficient gonadotropin suppression. Further large multi-centre studies are required to establish the contraceptive efficacy of the most promising steroid combinations.

Male Hormonal Contraception: A Double-Blind, Placebo-Controlled Study

“…Testosterone, and the more recently used androgen-progestin combinations, reversibly suppress spermatogenesis by suppressing the pituitary gonadotropins LH and FSH (5)(6)(7)(8). A recently published study with etonogestrel (ENG) implants combined with testosterone decanoate injections showed contraceptive efficacy (defined as 1 million sperm per milliliter or less) in almost 90% of the participants (9).…”

Update on Male Hormonal Contraception: Is the Vasectomy in Jeopardy?

“…8,[36][37][38][39][40][41][42][43] The purpose of this review was to summarize the published data regarding hormone-based male contraceptive treatment options.…”

Contribution of Recent Transgenic Models and Transcriptional Profiling Studies to Our Understanding of the Mechanisms by which Androgens Control Spermatogenesis

“…There is an overwhelming amount of data showing that defects in testicular androgen production, whether occurring spontaneously, or induced (for instance by contraceptive methods involving the administration of androgens and/or progestagens) disturb fertility [4][5][6]42]. There is also increasing evidence that defects in androgen signaling may have major effects on germ cell production [38,42].…”

“…Their secretion is tightly controlled by central regulators such as hypothalamic GnRH and by testicular feedback signals including the steroid hormones testosterone and 17 -estradiol and the peptide hormone inhibin B. Most efforts to develop pharmacological methods of male contraception have aimed at manipulating gonadotropin secretion with consequent suppression of intratesticular testosterone levels [4][5][6]. These efforts have now provided a firm base to develop an acceptable male contraceptive, but it is obvious that further improvements are needed and that alternative approaches should be considered.…”