Birth control is an umbrella term for several techniques and methods used to prevent fertilization or to interrupt pregnancy at various stages. Birth control techniques and methods include contraception (the prevention of fertilization), contragestion (preventing the implantation of the blastocyst) and abortion (the removal or expulsion of a fetus or embryo from the uterus). Contraception includes barrier methods, such as condoms or diaphragm, hormonal contraception, also known as oral contraception, and injectable contraceptives. Contragestives, also known as post-coital birth control, include intrauterine devices and what is known as the morning after pill.
The function of birth control can be classified by the stage of reproduction during which it is active. A form of birth control which prevents the sperm from fertilizing the egg is a contraceptive agent. A form of birth control which acts after fertilization to prevent or interrupt the implantation of the embryo into the uterine lining is a contragestive agent. After implantation has occurred, an agent which ends gestation by terminating the pregnancy is an abortifacient.
Safe sex is sexual activity engaged in by people who have taken precautions to protect themselves against sexually transmitted diseases (STDs) such as AIDS. It is also referred to as safer sex or protected sex, while unsafe or unprotected sex is sexual activity engaged in without precautions. Some sources prefer the term safer sex to more precisely reflect the fact that these practices reduce, but do not completely eliminate, the risk of disease transmission. In recent years, the term "sexually transmitted infections" (STIs) has been preferred over "STDs", as it has a broader range of meaning; a person may be infected, and may potentially infect others, without showing signs of disease.
Safe sex practices became more prominent in the late 1980s as a result of the AIDS epidemic. Promoting safe sex is now one of the aims of sex education. Safe sex is regarded as a harm reduction strategy aimed at reducing risks. The risk reduction of safe sex is not absolute; for example the reduced risk to the receptive partner of acquiring HIV from HIV seropositive partners not wearing condoms to compared to when they wear them is estimated to be about a four- to fivefold. Although some safe sex practices can be used as contraception, most forms of contraception do not protect against all or any STIs; likewise, some safe sex practices, like partner selection and low risk sex behavior, are not effective forms of contraception.
Safe sex is effective on avoiding STDs if only both parties involved in sexual intercourse agreed on doing so and stick to it. During intercourse using condoms, for example the panetrative male might intentionally pull off the condom and continue penetrating without the female (or male receptive partner) consent and notice. This is a high risk behavior that often betraying the trust as well as spreading the disease.