The global population is at an all time high at over 6 billion people. A large percentage of this population growth is in less developed countries where access to reproductive health care is limited. However, even in industrialized countries, including the United States, it is estimated that approximately 10-15% of all sexually active women use no birth control, contributing to the almost 50% unintended pregnancy rate (1). About 850,000 of these unintended pregnancies in the U.S. occur in teenagers. While 2% of U.S. women have an induced abortion every year (2), about half of the unplanned pregnancies are carried to term (1). The rates of unwanted pregnancy in the United States are at least four times higher than some countries in Europe and Japan (3). These differences do not appear to be explained solely by exposure to the risk of pregnancy since other countries such as the Netherlands and Sweden have teenagers who engage in sexual activity earlier than most teenagers in the United States (4). The cost of contraception to the consumer and lack of insurance coverage for contraception contribute to the high unintended pregnancy rate in the U.S. (2) However, the varied reasons for problematic contraceptive use have yet to be full elucidated and women in the United States are either not using their contraceptive method correctlyand consistently or are choosing methods with high failure rates. Therefore, more reliable contraception and contraceptive management are necessary to reduce the unintended pregnancy rate in the United States.

Safe and reliable family planning directly improves public health. New methods are an area of ongoing research, such as the development of microbicides which will fulfill the unmet dual need of contraception and protection against sexually transmitted infections/human immunodeficiency virus in women. Women provided with effective contraception are protected against events that may threaten their personal and professional independence. Pregnancy and childbirth pose substantial health risks that should be actively avoided unless pregnancy is desired. The chance of death due to pregnancy and childbirth varies geographically, but is always higher than that associated with currently available methods of contraception (5).

There is an ever increasing variety of contraceptives available to couples. Each method has its own distinct advantages and disadvantages. The ideal contraceptive would be effective, reversible, easy to use, not coitally dependant, safe, free of side effects, and inexpensive. Because one objectively perfect method does not yet exist, the choice of a family planning method should be individualized to each couple and may change during a woman's reproductive life. The majority of contraceptives currently available can be divided into two groups: barrier methods and hormonal methods. Both work by preventing the sperm and egg from coming in contact with one another. Barrier methods prevent sperm from entering the upper female genital tract. Hormonal contraceptives have three main mechanisms of action, which include ovulation inhibition, thickening of cervical mucus, and an alteration of the endometrium. There have been, and there will continue to be, great strides to modify and optimize these methods. This chapter will serve as a review of contraceptive options with focus on the mechanism of action, efficacy, and non-contraceptive effects.