Combined oral contraceptives

The combined oral contraceptive pill (COCP), often referred to as the birth control pill or colloquially as 'the pill', is a type of birth control that is designed to be taken orally by women. It includes a combination of an estrogen (usually ethinylestradiol) and a progestogen (specifically a progestin). When taken correctly, it alters the menstrual cycle to eliminate ovulation and prevent pregnancy.'The evidence is not yet clear that these still do in fact cause cancer or related to it. The FDA Advisory Committee made comments about this, that if there wasn't enough evidence to indicate whether or not these pills were related to the development of cancer, and I think that's still thin; you have to be cautious about them, but I don't think there is clear evidence, either one way or the other, that they do or don't cause cancer.'Mechanism of actionCOCs prevent fertilization and, therefore, qualify as contraceptives. There is no significant evidence that they work after fertilization. The progestins in all COCs provide most of the contraceptive effect by suppressing ovulation and thickening cervical mucus, although the estrogens also make a small contribution to ovulation suppression. Cycle control is enhanced by the estrogen.Because COCs so effectively suppress ovulation and block ascent of sperm into the upper genital tract, the potential impact on endometrial receptivity to implantation is almost academic. When the two primary mechanisms fail, the fact that pregnancy occurs despite the endometrial changes demonstrates that those endometrial changes do not significantly contribute to the pill's mechanism of action.Ten different progestins have been used in the COCs that have been sold in the United States. Several different classification systems for the progestins exist, but the one most commonly used system recapitulates the history of the pill in the United States by categorizing the progestins into the so-called 'generations of progestins.' The first three generations of progestins are derived from 19-nortestosterone. The fourth generation is drospirenone. Newer progestins are hybrids.First-generation progestins. First-generation progestins include noretynodrel, norethisterone, norethisterone acetate, and etynodiol diacetate… These compounds have the lowest potency and relatively short half-lives. The short half-life did not matter in the early, high-dose pills but as doses of progestin were decreased in the more modern pills, problems with unscheduled spotting and bleeding became more common.Second-generation progestins. To solve the problem of unscheduled bleeding and spotting, the second generation progestins (norgestrol and levonorgestrel) were designed to be significantly more potent and to have longer half-lives than norethisterone-related progestins... The second-generation progestins have been associated with more androgen-related side-effects such as adverse effect on lipids, oily skin, acne, and facial hair growth.Third-generation progestins. Third-generation progestins (desogestrel, norgestimate and elsewhere, gestodene) were introduced to maintain the potent progestational activity of second-generation progestins, but to reduce androgeneic side effects. Reduction in androgen impacts allows a fuller expression of the pill's estrogen impacts. This has some clinical benefits… On the other hand, concern arose that the increased expression of estrogen might increase the risk of venous thromboembolism (VTE). This concern introduced a pill scare in Europe until international studies were completed and correctly interpreted.Fourth-generation progestins. Drospirenone is an anologue of spironolactone, a potassium-sparing diuretic used to treat hypertension. Drospirenone possesses anti-mineralocorticoid and anti-androgenic properties. These properties have led to new contraceptive applications, such as treatment of premenstrual dysphoric disorder and acne… In the wake of concerns around possible increased VTE risk with less androgenic third-generation formulations, those issues were anticipated with drospirenone. They were clearly answered by large international studies.Next-generation progestins. More recently, newer progestins have been developed with properties that are shared with different generations of progestins. They have more profound, diverse, and discrete effects on the endometrium than prior progestins. This class would include dienogest (United States) and nomegestrol (Europe). The combined oral contraceptive pill (COCP), often referred to as the birth control pill or colloquially as 'the pill', is a type of birth control that is designed to be taken orally by women. It includes a combination of an estrogen (usually ethinylestradiol) and a progestogen (specifically a progestin). When taken correctly, it alters the menstrual cycle to eliminate ovulation and prevent pregnancy. They were first approved for contraceptive use in the United States in 1960, and are a very popular form of birth control. They are currently used by more than 100 million women worldwide and by almost 12 million women in the United States. From 2015-2017, 12.6% of women aged 15-49 in the US reported using oral contraception making it the second most common method of contraception in this age range with female sterilization being the most common method. Use varies widely by country, age, education, and marital status. One third of women aged 16–49 in the United Kingdom currently use either the combined pill or progestogen-only pill,compared with less than 3% of women in Japan (as of 1950-2014). Two forms of combined oral contraceptives are on the World Health Organization's List of Essential Medicines, the most important medications needed in a basic health system. The pill was a catalyst for the sexual revolution. Combined oral contraceptive pills are a type of oral medication that is designed to be taken every day, at the same time of day, in order to prevent pregnancy. There are many different formulations or brands, but the average pack is designed to be taken over a 28-day period, or cycle. For the first 21 days of the cycle, users take a daily pill that contains hormones (estrogen and progestogen). The last 7 days of the cycle are hormone free days. Some packets only contain 21 pills and users are then advised to take no pills for the following week. Other packets contain 7 additional placebo pills, or biologically inactive pills. Some newer formulations have 24 days of active hormone pills, followed by 4 days of placebo (examples include Yaz 28 and Loestrin 24 Fe) or even 84 days of active hormone pills, followed by 7 days of placebo pills (Seasonale). A woman on the pill will have a withdrawal bleed sometime during her placebo pill or no pill days, and is still protected from pregnancy during this time. Then after 28 days, or 91 days depending on which type a person is using, users start a new pack and a new cycle. If used exactly as instructed, the estimated risk of getting pregnant is 0.3%, or about 3 in 1000 women on COCPs will become pregnant within one year. However, typical use is often not exact due to timing errors, forgotten pills, or unwanted side effects. With typical use, the estimated risk of getting pregnant is about 9%, or about 9 in 100 women on COCP will become pregnant in one year. The perfect use failure rate is based on a review of pregnancy rates in clinical trials, the typical use failure rate is based on a weighted average of estimates from the 1995 and 2002 U.S. National Surveys of Family Growth (NSFG), corrected for underreporting of abortions.