of an egg by a sperm (conception) or prevention of attachment of the fertilized egg to the lining of the uterus (implantation Development of the Blastocyst A baby goes through several stages of development, beginning as a fertilized egg. The egg develops into a blastocyst, an embryo, then a fetus. During each normal menstrual cycle, one egg (ovum)... read more ).Contraception (birth control) is used to prevent pregnancy. Contraceptive methods may be temporary (for example, birth control pills or an intrauterine device) or permanent Permanent Contraception Permanent contraception involves making a person incapable of reproduction. Disrupting the tubes that carry sperm or the egg ends the ability to reproduce. This form of contraception should... read more (intended to avoid pregnancy permanently—for example, vasectomy Permanent Contraception for Men (Vasectomy) Permanent contraception involves making a person incapable of reproduction. Disrupting the tubes that carry sperm or the egg ends the ability to reproduce. This form of contraception should... read more or tubal ligation Permanent Contraception for Women Permanent contraception involves making a person incapable of reproduction. Disrupting the tubes that carry sperm or the egg ends the ability to reproduce. This form of contraception should... read more ). Abortion is a procedure that interrupts a pregnancy. It is used to end an unintended pregnancy when contraception has failed or not been used.
There are many methods of contraception. None is completely effective, but some methods are far more reliable than others. Effectiveness often depends on which method is used and how closely people follow instructions. Thus, the effectiveness of a birth control method can be described in two ways:
How well it prevents pregnancy when used by most people (typical use)
How well it prevents pregnancy when instructions for use are followed exactly (perfect use)
For example, oral contraceptives (birth control pills) are very effective if a woman takes them every day (perfect use). However, forgetting to take a few pills (typical use) decreases the effectiveness. In contrast,intrauterine devices, once inserted, require nothing more until they need to be replaced. Thus, typical use is usually the same as perfect use. People tend to follow instructions more closely as they get used to a method. As a result, the difference between effectiveness with perfect use and with typical use often decreases as time passes.
Besides its degree of effectiveness, each contraceptive method has other advantages and disadvantages. Choice of method depends on preferences, degree of reliability needed, and medical considerations.
If contraception fails, emergency contraception Emergency Contraception Emergency contraception is used after an act of unprotected sexual intercourse or after an occasion when a contraceptive method fails (for example, when a condom breaks). Emergency contraception... read more may help prevent an unintended pregnancy. Emergency contraception should not be used as a regular form of contraception.
More Information
The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
Planned Parenthood: This web site provides information about birth control, abortion, and other subjects related to reproduction.
