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Birth Control Overview (cont.)

What is the effectiveness, and what are the side effects of birth control pills?

Birth control pills

Birth control pills, also known as oral contraceptives, have been marketed in the United States since 1962. Over the past 40 years, there have been changes in the types of estrogen and progestin (hormones) used in the pills and lower amounts of hormones overall.

According to the Centers for Disease Control and Prevention, the birth control pill is the leading birth control method used by women under the age of thirty. Birth control pills today are designed to improve safety and reduce side effects. Lower doses of estrogen are associated with a decrease in side effects such as weight gain, breast tenderness, and nausea.

Birth control pills are available in an oral pill and chewable pill, usually taken by mouth and swallowed with a liquid. Over 30 different combinations of birth control pills are available in the United States. The majority of the pill combinations have 21 hormonally active pills followed by 7 pills containing no hormones. A woman begins by taking a pill on the first day of her period or the first Sunday after her period has begun. By taking a pill a day, a woman can usually take pills consistently throughout her cycle.

  • Effectiveness: Pregnancy rates range from 0.1% with perfect use to 5% with typical use.
  • Advantages: Birth control pills may be used to treat irregular menstrual periods. Women can manipulate their menstrual cycle to avoid a period during certain events, such as vacations or weekends by extending the number of intake days of hormonally active pills or by skipping the non-active pill week. Birth control pills help prevent certain conditions, such as benign breast disease, pelvic inflammatory disease (PID), and functional cysts. Functional cysts are reduced by the suppression of ovarian hormone production. Ectopic pregnancies are prevented by the inhibition of ovulation. Birth control pills have also been known to prevent certain ovarian and endometrial cancers.
  • Side effects of birth control pills: Problems encountered when in taking birth control pills include
    • nausea,
    • breast tenderness,
    • weight gain,
    • breakthrough bleeding,
    • absent periods,
    • headaches,
    • depression,
    • anxiety, and
    • diminished sexual desire.
  • Disadvantages: It's important to take the pills daily and consistently (same time every day). If a woman stops taking her birth control pills, it may take several months for her to resume normal ovulatory menstrual cycles. If 6 months elapse without the return of menstrual flow she may need to be examined by her health care provider.
  • Additional risks:
    • Some women may be at risk for blood clots (venous thrombosis). At particular risk are smokers over the age of 35, as well as women with elevated blood lipid (cholesterol) levels, diabetes, high blood pressure, and obesity.
    • The association of birth control pill use and breast cancer in young women is controversial. The Collaborative Group on Hormonal Factors in Breast Cancer performed the most comprehensive study to date in 1996. The results demonstrated that current pill users, and those who had used birth control pills within the past 1-4 years, had a slightly increased risk of breast cancer. Although these observations support the possibility of a marginally elevated risk, the group noted that the pill users had more breast examinations and breast imaging studies than the nonusers. Thus, although the consensus opines that birth control pills can lead to breast cancer, the risk is small and the resulting tumors spread less aggressively than usual. Current thought is that birth control pill use may be a cofactor that can interact with another primary cause to stimulate breast cancer.
    • The relationship between birth control pill use and cervical cancer is also quite controversial. Important risk factors for cervical cancer include early age of first sexual intercourse and exposure to the human papillomavirus. The current thinking is that if birth control pills contribute to the risk of cervical cancer, their impact is small and related to risky sexual behaviors. Thus, women who use birth control pills should have an annual Pap test.
  • STDs and birth control pills: Birth control pills do not provide protection from STDs.

Progestin-only birth control pills

Progestin-only pills, also known as the mini-pill, are not used widely in the United States. Less than 1% of women use oral contraceptives as their sole method of birth control. Those who use them include women who are breastfeeding or cannot take estrogen.

Medically Reviewed by a Doctor on 8/26/2016
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