Contraceptive technology: current and prospective methods.

Current studies of ways to inhibit fertility through surgical sterilization vaginal and intrauterine contraception hormonal suppresssion of ovulation hormonal contraception without suppressing ovulation (which includes research on interference with the male reproductive process) are presented in this comprehensive review. Laboratory research related to fertility control suggests potential methods for use by the female such as an antiovulatory pill injection or vaginal ring administered once a month or on a long-term basis (3-6 months) or a long-term implant. Similar types of administration have been suggested for continuous low-dose progestins as well as methods involving skin-contact absorption or the release of the steroid by the IUD. Other possibilities include compounds affecting the corpus luteum which would inhibit implantation monthly pills or injections vaginal tampons to cause luteolysis (administration on a nonregular basis has also been considered) a once-a-month antiprogestational pill precoital progestin postcoital estrogen antiestrogen or antizygotic agent taken orally immunization with sperm antigens immunization with steroid-binding proteins to affect the uterus and avoid interference with ovulation improved methods of detecting ovulation reversible tubal occlusion simplification of tubal ligation and intrauterine infusion of oxytoxins to induce sterility. Also under investigation are oral or parenteral preparations to assure multiple births at will and sex determination by immunization with Y sperm antigens or artificial insemination. Methods involving the male include a subdermal implant or periodic injection to suppress spermatogenesis subdermal implants of progestin or oral tablets of compounds to prevent maturation of sperm oral pills to alter the biochemical make-up of seminal fluid immunization with testes or sperm antigens and reversible vas deferens occlusion and ligation. Methods under consideration for use by either female or male involve oral preparations which alter the gonadotrophic hormone balance. Topical application of pheromones has also been suggested as a possibility.