- birth control pills
Oral contraceptives (OCPs), also called birth control pills, are medicines that are taken to prevent pregnancy. They are the most widely used methods of reversible birth control. OCPs work mostly by preventing the ovaries from releasing eggs.
What is the information for this topic?
Most OCPs use a combination of the hormones estrogen and progesterone. The woman takes an OCP for 21 to 25 days. She then may take inactive pills until day 28, just to stay in the routine of taking a pill each day. Inactive pills do not contain hormones. Some products include iron in the inactive pills. Most women begin their periods 2 or 3 days after they have taken the last estrogen-progesterone pill in the cycle.
Some women may be told by their healthcare providers to take OCPs continuously without any inactive pills or breaks in the cycle. This approach may be helpful for women who have moderate to severe premenstrual syndrome. It can also be helpful in treating migraine headaches.
Uses of oral contraceptives The most common uses of oral contraceptives are:
- decreasing premenstrual symptoms
- preventing pregnancy
- regulating the menstrual cycle
- treating acne
- treating dysfunctional uterine bleeding
OCPs do not prevent sexually transmitted infections (STIs). Safer sex practices, such as using condoms along with the pill, can reduce, but not eliminate, the risk of STIs.
EffectivenessWhile a woman is on OCPs, the brain no longer signals the ovaries to produce an egg each month. OCPs, when taken perfectly, have a failure rate of no more than 2% to 3% when taken exactly as prescribed.
The most common reasons for failure are:
- forgetting to take the pill at the same time every day
- poor absorption of the pill from the stomach into the bloodstream, which can be caused by diarrhea, vomiting, and the use of some antibiotics
- taking OCPs with other medicines or supplements that may make them less effective, such as carbamazepine (i.e., Carbatrol, Tegretol, Equetro), phenytoin (i.e., Dilantin, Phenytek), phenobarbital, Saw Palmetto, and rifampin (i.e., Rifadin, Rimactane). Women who are prescribed rifampin to treat an infection and who are also on OCPs, are advised to use a barrier method of contraception for the duration of the monthly cycle in which rifampin is used.
- using OCP's that have expired dates
Contraindications Oral contraceptives should not be used by women who have had:
- deep venous thrombosis or pulmonary embolus
- breast cancer
- cancer of the uterus
- certain heart disorders
- impaired liver function, such as cirrhosis
- unexplained vaginal bleeding between periods
Smoking, uncontrolled high blood pressure or diabetes, and obesity may make the pill unsafe for a woman over 35. Prior to beginning the pill, a woman needs to have a physical exam, including a pelvic exam and Pap smear. The healthcare professional may order blood tests to check blood glucose and cholesterol levels.
Side effects Side effects of taking oral contraceptives are:
- breast tenderness, pain, and discharge
- change in sex drive
- irregular spotting or vaginal bleeding
- leg pain, cramps, or swelling
- mood swings
- weight loss or weight gain
When a woman is started on an OCP, she is usually asked to try them for 2 to 3 months. This allows her body to adjust to the changes in hormone levels. If a woman continues to have side effects, it may be possible to change to a different OCP. It is important for a woman to discuss any side effects she may be having with her healthcare professional. Often changing to a different pill causes the side effects to subside.
After a woman stops taking the pill, it may take a period of months for her periods, and her fertility, to return.
Serious complications include:
- deep venous thrombosis or pulmonary embolus
- heart attack
- high blood pressure
- a slightly increased risk of breast cancer
If a woman develops any of the following side effects, she should stop her OCPs and call her healthcare professional immediately:
- chest pain
- leg pain
- severe headache
- severe stomach pain
- swelling of one or both legs
- visual impairments, including blurred vision or seeing bright lights
In addition, the mechanisms of action of an OCP should be explained by the healthcare professional to a woman who is considering using the device. Women who believe life begins at conception may not be comfortable using a method of birth control that can, even infrequently, prevent an embryo from implanting in the uterus, and thus to be lost.
Even though experts debate whether this post-fertilization effect may occur with an OCP, since there is no conclusive proof that it cannot happen, thus may be possible, women should be informed of this debate and this possibility.