Contraception: an international perspective

Although it is estimated that the population growth rate will decline to a replacement level by 2050, it is also now predicted that the total world population will reach 8.9 billion in that year -- far higher than the 2004 estimate of 6.4 billion. More than 26 billion new couples will need contraceptives in the next half century. Although a steady increase in contraceptive use has been observed in both developed and developing countries, the contraceptive needs of a high percentage of couples have not yet been met and the number of unplanned pregnancies continues to increase. The actual use of contraception differs from region to region. Although no new method has been registered for many years, several new products have been marketed during the last 5. Among these are new implants, medicated intrauterine systems, contraceptive vaginal rings, transdermal patches and several new combined oral contraceptive formulations. New contraceptive methods have been developed to meet the objectives of expanding contraceptive choices for both women and men and answering an unmet need for contraceptives with a long-term action that meet the expectations of consumers. Simplicity, reversibility and effectiveness are the desired features of a male contraceptive, but no new male contraceptive method is yet available. New areas of basic research include studies on genes, proteins and enzymes involved in the reproductive system. The new methods will be targeted to specific interactions within the reproductive system at the level of ovaries and testes, as well as between spermatozoa and ova. This futuristic approach still keeps in mind the need for better access to existing contraceptive methods, as well as the discovery of new contraceptives that are simple to use, safe, reversible and inexpensive. In the future, contraceptives may be combined with other medicinal agents to provide dual protection against both pregnancy and other preventable conditions, such as sexually transmitted infections.