If a woman is sexually active and she is fertile — physically able to become pregnant — she needs to ask herself, "Do I want to become pregnant now?" If her answer is "No," she must use some method of birth control (contraception).
If a woman does not want to get pregnant at this point in her life, when does she plan to become pregnant? Soon? Much later? Never? Her answers to these questions can determine the method of birth control that she and her male sexual partner use — now and in the future.
There are a number of different ways to describe birth control. Terms include contraception, pregnancy prevention, fertility control, and family planning. But no matter what the process is called, sexually active people can choose from a plethora of methods to reduce the possibility of their becoming pregnant. Nevertheless, no method of birth control available today offers perfect protection against sexually transmitted infections (sexually transmitted diseases, or STDs), except abstinence.
It is estimated that there are 3.6 million unplanned pregnancies every year in the United States. Half of these unplanned pregnancies happen because a couple does not use any birth control at all, and the other half occur because the couple uses birth control, but not correctly.
In simple terms, all methods of birth control are based on either preventing a man's sperm from reaching and entering a woman's egg (fertilization) or preventing the fertilized egg from implanting in the woman's uterus (her womb) and starting to grow.
Birth control methods can be reversible or permanent. Reversible birth control means that the method can be stopped at essentially any time without long-term effects on fertility (the ability to become pregnant). Permanent birth control usually means that the method cannot be undone or reversed, most likely because it involved surgery. Examples of permanent methods include vasectomy for the man or tubal ligation for the woman.
Birth control methods can also be classified according to whether they are a barrier method (for example, a condom) that blocks sperm, a mechanical method (for example, an intrauterine device), or a hormonal method (for example, the "pill").
"Natural" methods do not rely on devices or hormones but on observing some aspect of a woman's body physiology in order to prevent fertilization.
The direct responsibility for most of the methods of birth control that are currently available rests with the woman. The input of a health care provider may sometimes be essential in choosing appropriate birth control. New methods of birth control are being developed and tested all the time. And what is appropriate for a couple at one point may change with time and circumstances.
Unfortunately, no birth control method, except abstinence, is considered to be 100% effective.