Male fertility regulation: the challenges for the year 2000.

The search for new, safe, effective and reversible contraceptive methods for men is being pursued by several agencies. The most likely developments before the year 2000 would appear to be: the introduction of more easily reversed procedures of vas occlusion; hormonal means of sperm suppression based on infrequent injections of androgens either alone or combined with other gonadotrophin-suppressing agents. Methods based on new drugs or vaccines are unlikely to be developed by the end of the decade. Research is needed to understand the basis of the differences in efficacy of contraceptive steroids in men of different ethnic origin. Equally there is a need to monitor the safety and acceptability of hormonal methods for men. New targets for drug intervention should be pursued through support of basic science, taking advantage of modern cellular and molecular biological techniques. Finally, the subject of Andrology needs to be strengthened throughout the world so that scientists in developing countries can participate fully in this work.