Reversible Male Contraception: New Technologies and Perspectives
摘要
While there are several easy-to-use reversible female contraceptives, little is available for men. Introduction of novel, cost-effective male contraceptives could have important downstream global health and economic benefits. Currently, nearly half of all pregnancies globally are unintended, with many often resulting in unsafe abortions, which are still a burden in many countries. Available options for male contraception include male condom or withdrawal, both with high failure rates, and vasectomy, which is not easily reversible. Advanced methods of male hormonal contraception include combinations of progestin and androgen. The progestin agents suppress the gonadotropins, leading to the suppression of both testosterone and the spermatogenesis with full reversibility within a few months. The androgen replaces the suppressed endogenous testosterone. Modified androgens are also being studied as they may ensure both sperm suppression and androgenic actions in a single oral pill. Novel, nonhormonal contraception products decrease sperm motility, or accelerate the acrosome reaction to prevent fertilization. Only one new molecule is in the clinical stage of development, while other approaches are still in early-stage research, and reversible methods of vasectomy are also in proof-of-concept trials. The search for novel methods must continue to offer several options to men, allowing shared responsibility in the couple’s fertility regulation, and to curb maternal mortality.