Margaret Sanger was the first to envision oral contraceptives (the birth control pill, or simply “the pill”). Many researchers had been working with chemical methods to inhibit pregnancy in animals, but they were reluctant to try these methods on humans because they feared that increasing hormones could cause cancer. The complexity of a woman’s body chemistry and the expense involved in developing the pill inhibited its progress. Finally, in 1960, the birth control pill was federally approved as a contraceptive method.

At first, the pill was much stronger than it needed to be. In the search for the most effective contraception, more estrogen was seen as more effective. However, within 3 to 4 years, physicians realized that many women were experiencing negative side effects due to the high dosage of estrogen, so they lowered the amount of estrogen. Today’s birth control pills have less than half the dose of estrogen the first pills had. After 40 years on the market, oral contraceptives still remain the most popular contraceptive method not only in the United States but around the world (Freeman, 2002; Lie, 2000). In addition, birth control pills are the most extensively studied type of medication in the history of medicine (Hatcher et al., 2004).

Combination birth control pills, which contain synthetic estrogen and a type of progesterone, are the most commonly used contraceptive method in the United States. They require a physician’s prescription and cost between $12 and $25 per month at the pharmacy (less in family planning clinics).

In Chapter 4 we discussed menstrual manipulation and menstrual suppression. Birth control pills have typically been designed to mimic an average menstrual cy­cle, which is why a woman takes them for 21 days and then has 1 week off, in which she will usually start a period. Originally, this 3-week-on/1-week-off regi­men was developed to convince women that the pill was “natural,” which pill makers believed would make the product more acceptable to potential users and reassure them that they were not pregnant every month (Clarke & Miller, 2001; Thomas & Ellertson, 2000). As we discussed in Chapter 4, the bleeding that women experience while on the pill is medically induced and has no physiologi­cal benefit (J. L. Schwartz et al., 1999).

Monthly withdrawal bleeding while on oral contraceptives may soon become obso­lete altogether. Some healthcare providers have begun the practice of “bicycling” (back – to-back use of two packs of active pills without only placebo pills at the end of the sec­ond pack) or “tricycling” (back-to-back-back use of three packs of active pills with placebo pills only after the third pack; Hatcher & Nelson, 2004). In 2003 the FDA ap­proved a new continuous 84-day active pill with a 7-day placebo pill regimen called Seasonale. Users of Seasonale have only 4 periods a year, compared to the usual 13. Seasonale and other birth control pill manipulation routines may be attractive options for women who experience heavy bleeding and cramping with their periods each month. Research has found that 60% of women report a preference for no period while taking oral contraceptives (Lie, 2000).

How They Work The hormones estrogen, progesterone, lutenizing hormone (LH), and follicle stimulating hormone (FSH) fluctuate during a woman’s menstrual cycle. These fluctuations control the maturation of an ovum, ovulation, the development of the endometrium, and menstruation (see Chapter 4). The synthetic hormones replace a woman’s own natural hormones but in different amounts. The increase in estrogen and progesterone prevent the pituitary gland from sending hormones to cause the ovaries to begin maturation of an ovum. Hormone levels while on the pill are similar to when a woman is pregnant, and this is what interferes with ovulation. Birth control pills also work by thickening the cervical mucus (which inhibits the mobility of sperm) and by re­ducing the buildup of the endometrium.

Combination birth control pills can either be monophasic or multiphasic. Monophasic pills contain the same amount of hormones in each pill, whereas multi­phasic pills vary the hormonal amount. Traditionally, birth control pills have always been taken on either a 21-day or 28-day regimen and started on the 1st or 5 th day of menstruation or on the 1st Sunday after menstruation. Start days vary depending on the pill manufacturer. The majority of manufacturers recommend a Sunday start day, which enables a woman to avoid menstruating during a weekend. Each pill must be taken every day, at approximately the same time. This is important because they work by maintain­ing a certain hormonal level in the bloodstream. If this level drops, ovulation may occur (see the accompanying Sex in Real Life, “What to Do If You Forget,” for more informa­tion). The last seven pills in a 28-day regimen are placebo pills and, because they con­tain no hormones, a woman usually starts menstruating while taking them.

Women who take birth control pills usually have lighter menstrual periods because the pills decrease the buildup of the endometrium. Menstrual discomfort, such as cramp­ing, is also reduced. Because oral contraception also increases menstrual regularity, some women with irregular periods are advised to take birth control pills to regulate their pe­riods even if they do not need contraception. Contraceptive pill users may also experi­ence slight breast enlargement due to increases in estrogen. Research has found that 30% of women who take birth control pills experience increased breast size and/or breast tenderness (Hatcher & Nelson, 2004).

Because different pills contain different dosages of estrogen and progesterone, a healthcare provider needs to determine the sensitivity of a woman’s endocrine system to prescribe the appropriate level of hormones. There is no one type of pill that is better for everyone, based on side effects or effectiveness rates.

Before starting a regime of birth control pills, a woman must first have a full med­ical examination. Women with a history of circulatory problems, strokes, heart disease, breast or uterine cancer, hypertension, diabetes, and undiagnosed vaginal bleeding are generally advised not to take oral contraceptives (Hatcher et al., 2004). Although mi­graine headaches have typically been a contraindication for using birth control pills, some women may experience fewer migraines while using birth control pills, especially if used continuously without placebo pills (Hatcher et al., 2004). If a woman can use birth control pills, physicians usually begin by prescribing a low-dose estrogen pill, and they increase the dosage if breakthrough bleeding or other symptoms occur.

Подпись:Подпись:Triphasil (TRY-fay-sill) pills were introduced in the 1990s and have been growing in popularity. They contain three different sets of pills for the month. Each week, the hormonal dosage is increased, rather than keeping the level at the consistently high lev-

els like monophasic pills. When it was first introduced, many physicians liked this pill because it seemed to follow a woman’s natural cycle. However, many women who use triphasil pills report an increase in breakthrough bleeding due to the fluctuating hor­mone levels.

Because the hormones in birth control pills are similar to those during pregnancy, it is not surprising that many women experience signs of pregnancy. These signs may in­clude nausea, increase in breast size, breast tenderness, water retention, headaches, in­creased appetite, fatigue, depression, decreased sexual drive, and high blood pressure (Hatcher et al., 2004; see Chapter 12). Symptoms usually disappear within a couple of months, once a woman’s body becomes used to the hormonal levels.

Physicians should reevaluate a woman on birth control pills after 3 months to see whether she is experiencing any problems, in which case a different dosage may be in­dicated. If a woman using the pill experiences abdominal pain, chest pain, severe headaches, vision or eye problems, and severe leg or calf pain, she should contact her physician immediately. In addition, a woman who takes birth control pills should always inform her physician of her oral contraceptive use, especially if she is prescribed other medications or undergoes any type of surgery. Certain drugs may have negative interac­tions with oral contraceptives (see the accompanying Sex in Real Life, “Drugs and Herbs That Interact With Oral Contraception”).

Finally, over the last few years there has been a very vocal debate about whether oral contraceptive use increases a woman’s risk of developing breast cancer (Fowke et al.,

2004) . But research has found that using birth control pills, even when begun at a young age, has little, if any, effect on the development of breast cancer (Hatcher et al., 2004). In addition, even birth control pill users with a family history of breast cancer do not

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