RESUMO
The twentieth century began with approximately 1.6 billion human beings in the world and, with an increase of 96 million people per year, will end with over 6 billion people. Unless this trend is directly confronted by the world governments and their citizens, there will be nearly 8 billion by 2025 and over 11 billion by 2050. Thus, reproductive health is and will remain an issue of critical importance for all countries to realize and study. Part of this trend is because of the many pregnancies which occur in adolescents around the world. A number of issues have developed this century contributing to the many pregnant teenagers. For example, India has one of the world's largest populations of teenagers--over 23 million, representing over 26% of the total in the world. Effective methods for contraception and sexually transmitted diseases prevention are available, but not to all sexually active humans. However, many barriers to effective contraception exist around the globe. This article discusses some of them and also reviews use of contraceptive methods in various countries. These include oral contraceptives, emergency contraceptives, injectable and implantable contraceptives, intrauterine devices, barrier contraceptives and others. Reproductive health remains a critical, universal issue for all humans in the world. We all must examine the many pitfalls to controlling the world's populations, including lack of sex education, limited access to effective contraceptives, and others. We cannot afford to let the population continue unchecked. Effective strategies are needed at this time; otherwise, the population will continue to run out of control, negatively damaging the world for the coming generations. There is need to leave a positive, and not negative legacy for the next generation.