[Hormonal contraception for males--an option for adolescents?]

Although effective contraceptive methods are available, the incidence of teenage pregnancies and consecutive pregnancy interruptions remains high in industrial nations, including Germany. There are several reasons for this high incidence. Apart from earlier sexual maturation, the absence of contraceptive use or the use of inefficient methods contributes mainly towards this increase. Existing contraceptive methods for men either show unsatisfying efficacy (coitus interruptus, use of condoms) or problems of reversibility (vasectomy), which limits their broader use. Of the different experimental approaches towards male contraception, the hormonal approach is closest to practical implementation. Androgens are an essential part of all experimental approaches to hormonal contraception in males; they cause suppression of spermatogenesis through gonadotropin suppression. Previous clinical trials have validated the concept of hormonal contraception in men. However, the application modalities and the ineffectiveness of all self-administered androgen preparations have been unacceptable for practical use. Therefore recent developments focus either on androgen implants or on injectable, long-acting testosterone esters in combination with progestins, which also suppress gonadotropin secretion. Over the last decades various combinations of androgen preparations with different progestins or GnRH antagonists have been tested in clinical trials. Of these, testosterone with either depot medroxyprogesterone acetate, norethisterone, desogestrel or etonogestrel have shown promising efficacy in phase II clinical trials. However, whether hormonal contraception might be given to adolescent males remains to be elucidated. This will have to be assessed once a hormonal contraceptive for men has reached the market. Special attention will need to be given to bone maturation as androgens at the prescribed doses might induce premature closure of the epiphyseal joints.