Oral contraceptives are used to prevent pregnancy by creating a hormonal balance of the body that makes women temporarily unable to conceive.
Oral contraceptives, commonly referred to as "the pill," are used to prevent pregnancy by disrupting, and more or less replacing, the natural, hormonally-controlled menstrual cycle. The successful function of the pill relies on the continuous release of the hormones it contains into the body. This means that it must be taken daily to prevent pregnancy.
The pill contains a combination of synthetic (meaning made artificially, rather than by the body) estrogen and progestin (a form of progesterone), which act to replace the estrogen and progesterone normally made by the body. The estrogen in the pill suppresses the production of follicle stimulating hormone (FSH), which is instrumental in developing eggs in the ovaries. When FSH is suppressed, the eggs never reach maturity and cannot be released or fertilized by sperm. The lack of FSH also prevents the body from increasing estrogen production, which in turn prevents the characteristic thickening of the uterine lining (the endometrium), in preparation for pregnancy. These chemical activities take place in the first week to ten days of the menstrual cycle.
By mid-cycle, the consistent low levels of progesterone, in the form of progestin, in the body prevent the release of the egg. Progestin also makes it impossible for a fertilized embryo to implant in the uterus wall, and keeps the cervical mucus, which in fertile women thins in preparation for penetration by sperm, thick and impenetrable.
At the end of the cycle, women either cease taking the pill entirely for a period of seven days, or they take placebo or reminder pills, also called "blanks," which lack estrogen and progestin for seven days. During this time, the uterus is able to break down its thin lining, and the lining is then released with some blood in a process that mimics natural menstruation.
The pill, in addition to its obvious application as a form of birth control, may also be prescribed for women who have irregular, excessively heavy, or painful periods, because the process regulates hormones in such a way that such symptoms may be reduced or eliminated entirely.
While the pill is very effective as a form of birth control, it does not prevent sexually transmitted diseases (STDs) in any way, and doctors and health care practitioners emphatically recommend that the only way to prevent STD infections is by using condoms or abstaining from sex entirely.
Additionally, some women may react to orally administered hormones with symptoms similar to those of menopause, such as sudden hot flashes, mood swings, and changes in appetite and sex drive. The use of newer "low-dose" pills or progestin-only pills, may alleviate these symptoms. Some women may experience depression, weight gain or loss, and changes in breast size. Long-term use of hormones such as those present in the birth control pill can also be dangerous for those with a history of circulatory problems; blood clots, heart attack, or stroke can be a risk. While they are rare, severe reactions to synthetic hormones may occur. Some women may find that the pill is not right for them because of these reasons. But, according to many health experts and researchers (including those who compiled an informational Internet site in conjunction with The Pill, a recent episode of PBS’s popular news show The American Experience), the health risks associated with oral contraceptives are statistically lesser than those associated with pregnancy.
Ultimately, each woman’s experience with the birth control pill will be different, and women should consult with their doctors to find safe, effective means of maintaining their reproductive health and controlling their right to conceive or not.
Last updated: 06-Jun-07