Combined oral contraceptive pill in the context of "Estrogen (medication)"

Abortion is the termination of a pregnancy by removal or expulsion of an embryo or fetus. The unmodified word abortion generally refers to induced abortion, or deliberate actions to end a pregnancy. Abortion occurring without intervention is known as spontaneous abortion or "miscarriage", and occurs in roughly 30–40% of all pregnancies. Common reasons for inducing an abortion are birth-timing and limiting family size. Other reasons include maternal health, an inability to afford a child, domestic violence, lack of support, feelings of being too young, wishing to complete an education or advance a career, and not being able, or willing, to raise a child conceived as a result of rape or incest.

When done legally in industrialized societies, induced abortion is one of the safest procedures in medicine. Modern methods use medication or surgery for abortions. The drug mifepristone (aka RU-486) in combination with prostaglandin appears to be as safe and effective as surgery during the first and second trimesters of pregnancy. Self-managed medication abortion is highly effective and safe throughout the first trimester. The most common surgical technique involves dilating the cervix and using a suction device. Birth control, such as the pill or intrauterine devices, can be used immediately following an abortion. When performed legally and safely on a woman who desires it, an induced abortion does not increase the risk of long-term mental or physical problems. In contrast, unsafe abortions performed by unskilled individuals, with hazardous equipment, or in unsanitary facilities cause between 22,000 and 44,000 deaths and 6.9 million hospital admissions each year — responsible for between 5% and 13% of maternal deaths, especially in low-income countries. The World Health Organization states that "access to legal, safe and comprehensive abortion care, including post-abortion care, is essential for the attainment of the highest possible level of sexual and reproductive health". Public health data show that making safe abortion legal and accessible reduces maternal deaths.

The sexual revolution, also known as the sexual liberation, was a social movement that challenged traditional codes of behavior related to sexuality and interpersonal relationships throughout the Western world from the late 1950s to the early 1970s. Sexual liberation included increased acceptance of sexual intercourse outside of traditional heterosexual, monogamous relationships, primarily marriage. The legalization of "the pill" as well as other forms of contraception, public nudity, pornography, premarital sex, homosexuality, masturbation, alternative forms of sexuality, and abortion all followed.

The term "first sexual revolution" is used by scholars to describe different periods of significant change in Western sexual norms, including the Christianization of Roman sexuality, the decline of Victorian morals, and the cultural shifts of the Roaring Twenties. Sexual revolution most commonly refers to the mid-20th century, when advances in contraception, medicine, and social movements led to widespread changes in attitudes and behaviors around sex. The sexual revolution was influenced by Freud's theory of unconscious drives and psychosexual development, Mead's ethnographic work on adolescent sexuality in Samoa, Unwin’s cross-cultural studies, and the research of Kinsey and later Masters and Johnson, all of which challenged traditional beliefs about human sexuality.

Hormonal contraception refers to birth control methods that act on the endocrine system. Almost all methods are composed of steroid hormones, although in India one selective estrogen receptor modulator is marketed as a contraceptive. The original hormonal method—the combined oral contraceptive pill—was first marketed as a contraceptive in 1960. In the ensuing decades, many other delivery methods have been developed, although the oral and injectable methods are by far the most popular. Hormonal contraception is highly effective: when taken on the prescribed schedule, users of steroid hormone methods experience pregnancy rates of less than 1% per year. Perfect-use pregnancy rates for most hormonal contraceptives are usually around the 0.3% rate or less. Currently available methods can only be used by women; the development of a male hormonal contraceptive is an active research area.

There are two main types of hormonal contraceptive formulations: combined methods which contain both an estrogen and a progestin, and progestogen-only methods which contain only progesterone or one of its synthetic analogues (progestins). Combined methods work by suppressing ovulation and thickening cervical mucus; while progestogen-only methods reduce the frequency of ovulation, most of them rely more heavily on changes in cervical mucus. The incidence of certain side effects is different for the different formulations: for example, breakthrough bleeding is much more common with progestogen-only methods. Certain serious complications occasionally caused by estrogen-containing contraceptives are not believed to be caused by progestogen-only formulations: deep vein thrombosis is one example of this.

A contraceptive patch, also known as "the patch", is a transdermal patch applied to the skin that releases synthetic oestrogen and progestogen hormones to prevent pregnancy. They have been shown to be as effective as the combined oral contraceptive pill with perfect use, and the patch may be more effective in typical use.

Xulane and Twirla are approved for use in the United States. Evra is approved for use in Canada and marketed by Janssen Inc., and it is approved for use in the United Kingdom and in Europe and marketed by Janssen-Cilag. The patches are packaged in boxes of three and are only available by prescription.

Combined hormonal contraception (CHC), or combined birth control, is a form of hormonal contraception which combines both an estrogen and a progestogen in varying formulations.

The different types available include the pill, the patch and the vaginal ring, which are all widely available, and an injection, which is available in only some countries. They work by mainly suppressing luteinising hormone (LH) and follicle-stimulating hormone (FSH) and in turn preventing ovulation.

Progestogen-only pills (POPs), colloquially known as "mini pills", are a type of oral contraceptive that contain synthetic progestogens (progestins) and do not contain estrogens. They are primarily used for the prevention of undesired pregnancy, although additional medical uses also exist.

Progestogen-only pills differ from combined oral contraceptive pills (COCPs), which consist of a combination of progestins and estrogens.