Contraception--a look forward, Part I: New spermicides and natural family planning

The number of contraceptive choices for couples in the United States has declined in recent years, as has public and corporate sponsorship of the development of new contraceptives. Nevertheless, there are many possibilities for future birth control methods under active investigation. Six of the most interesting of these are described in this three-part review. Part I examines new spermicides and natural family planning. Current spermicides, though popular, are limited in number, have strict requirements for effective use, and cause a number of side effects. Investigational agents promise greater efficacy, simpler use, longer duration, and fewer adverse effects. Natural family planning methods are the only ones acceptable to a large number of couples, but they are seriously flawed by unacceptably low use-effectiveness and intensity of training requirements. Home chemical assays for biological markers of the fertile period, including urinary hormones and cervical enzymes, may improve the acceptability and effectiveness of natural family planning.