Contraception, or birth control, is the use of a medication, device or other method to prevent pregnancy. Contraceptives can work in a number of ways:
Blocking ovulation, the release of eggs from a woman's ovary
Preventing sperm from getting into the uterus and fallopian tubes (where fertilization of the egg by the sperm normally occurs)
Preventing implantation of the embryo (fertilized egg) into the uterine lining (endometrium)
Most women of reproductive age in the United States use some form of contraception. However, unintended pregnancy is still a common problem in this country. The apparent failure of contraception may result from several factors, including improper use, failure to follow treatment recommendations (noncompliance) or failure of the medication, device or method itself.
Learning about available contraceptive techniques, understanding which factors should be considered in your decision-making, and receiving guidance from your doctor are essential in determining the method(s) most appropriate and effective for your specific family planning and reproductive health needs.
Most contraceptive methods are very effective if used properly. Certain contraceptives, such as intrauterine devices (IUDs) and injectable contraceptives, are consistently associated with a low pregnancy rate. This is because compliance (using the method correctly or taking the medication on a regular basis) is not a major factor.
Oral contraceptives, or "birth control pills," are associated with a low pregnancy rate if they are taken properly. However, studies indicate that the actual pregnancy rate is much higher because many women do not take the pill every day as directed.
Other contraceptive methods, such as the condom, diaphragm/cervical cap and spermicides, can be very effective if used properly. However, these methods are also associated with higher "actual" pregnancy rates because of not using the method consistently or properly. Contraceptive methods that are specifically designed for use during intercourse and require decisions shortly before or at that time (e.g., the condom or diaphragm) are generally less effective than "longer-term" contraceptive methods.
Types of Contraception
Contraceptive methods, devices and medications include:
Hormonal contraceptives, including pills, skin patches and vaginal rings
Intrauterine devices (IUDs)
Withdrawal (coitus interruptus)
Oral contraceptives, also referred to as "the pill," in general contain a combination of the female hormones estrogen and progestin (a progesterone-like medication). The combined pill reduces the risk of pregnancy by:
Keeping the mucus in the cervix thick and impenetrable to sperm
Preventing implantation of a fertilized egg in the uterine lining
The only injectable contraceptive currently available in the United States is medroxyprogesterone acetate or DMPA (Depo-Provera). DMPA is injected deep into muscle, such as that of the buttock or upper arm, once every three months. DMPA alters the cervical mucus and endometrium, making the cervix impenetrable to sperm and preventing implantation of a fertilized egg. It also helps prevent ovulation, but not as reliably as the pill.
Transdermal Contraceptives (Skin Patches)
Transdermal contraceptive patches containing both estrogen and progestin have been shown to be effective. Some women may prefer a skin patch over a pill. Risks are similar to those with oral contraceptive pills.
A vaginal ring (Nuvaring) that releases estrogen and progestin is worn for three weeks followed by one week off (during which time a period occurs).
This type of contraceptive physically blocks or otherwise prevents sperm from entering the uterus and reaching the egg for fertilization. Barrier contraceptives include the condom, diaphragm and cervical cap. These contraceptive methods:
Have fewer side effects than hormonal contraceptives
Offer effective protection against certain sexually transmitted diseases (STDs)
May be available without a prescription (condom and spermicides)
Spermicides are chemical substances destructive to sperm. They are also available over the counter and are typically recommended in combination with barrier contraceptives (to help maximize the contraceptive effect).
The condom is a relatively thin, flexible cover placed over the penis to prevent semen from entering the vagina during sexual intercourse. When used properly, in addition to preventing pregnancy, condoms may offer protection to both partners against STDs and infection with human immunodeficiency virus (HIV).
Intrauterine Devices (IUDs)
IUDs are inserted by a physician into the uterus through the vagina and cervix. The currently available IUDs are safe and effective methods of contraception:
Copper-containing IUDs prevent pregnancy by inducing an inflammatory reaction within the endometrium, thereby keeping sperm from reaching the fallopian tubes. Copper-containing IUDs remain effective for approximately 8 to 10 years.
Levonorgestrel-releasing IUDs decrease menstrual blood loss by 40 to 50 percent and decrease pain associated with periods. Although highly effective, some women discontinue it because of complete cessation of menstrual bleeding.
Sterilization renders an individual sterile, or unable to reproduce. These methods, including tubal ligation and vasectomy, are the most effective form of contraception. Although these procedures may be reversible and subsequent operations may restore fertility, sterilization should always be considered permanent. Therefore, such procedures should only be performed after careful discussions with your physician and other members of your health care team.
It is important to speak with a physician to determine the contraceptive method(s) that will most appropriately and effectively fulfill your specific family planning and reproductive health needs. Because every patient is different, it is important that your situation is evaluated by someone who knows you as a whole person.