Birth control pills (also known as oral contraceptives) are a combination of two hormones, estrogen and progesterone. Both hormones are combined in a single tablet. When these pills are taken as prescribed by your doctor, they are 99.5 - 99.9% effective in preventing pregnancy. However, practically speaking, given that some people will occasionally forget to take the pill as directed, 6 out of every 100 women can expect to become pregnant in the first year of using the birth control pill (BCP).

The hormones in BCP's mimic early pregnancy. As such, they lead to the following effects:

• No ovulation: when you are pregnant or when you take birth control pills, your ovaries do not release any eggs.
• Changes in the lining of your uterus: this effect of BCP's usually leads to lighter menstrual periods.
• Thickening of cervical mucous: this effect of BCP's prevents sperm from entering the uterus.

• Prevention of undesired pregnancy
• Decreased incidence of pelvic inflammatory disease
• Decreased risk for ovarian and uterine cancer
• Decrease in severity of menstrual cramps
• May improve acne
• Reduces the incidence of benign cysts in both the ovary and the breast

• Blood clots: BCP's increase the risk of developing blood clots but this risk is particularly high in women who smoke. Women who have had blood clots in the past are also at increased risk.
• Stroke: The risk of stroke is limited to women who are over 35 and smoke. If you take BCP's, DON'T SMOKE.
• High blood pressure: If you already have high blood pressure, you should consider an alternative form of birth control. If you must use BCP's, you need to have your blood pressure monitored and the BCP's will need to be stopped if you blood pressure can not be adequately controlled.
• Diabetes: BCP's do not cause diabetes but if you have a predisposition for diabetes, you may have poorer control of your blood sugar while taking birth control pills.
• Gall bladder problems: Taking birth control pills may increase your risk of developing gallstones.
• Breast cancer: The risk of BCP's and breast cancer is controversial. The most recent epidemiologic studies do NOT show an increased risk of breast cancer in users of BCP's.
• Migraine headaches: This side effect mainly occurs in women who already have a history of migraine headaches. You may notice an increase in the frequency of your headaches after starting BCP's.

Any woman with the following conditions should NOT take OCP's:

• If you ever have had a blood clot.
• If you have ever had a stroke or heart attack.
• If you ever had breast cancer or cancer of the uterus.
• If you have abnormal vaginal bleeding when no cause has yet to be determined.
• If you have had liver problems especially if they were associated with a prior pregnancy.
• if you are currently pregnant.

The most common way of starting birth control pills is as follows:

• Start taking the pills on the first Sunday after the first day of your menstrual period.
• Try to take the pills at approximately the same time every day. ( Doing this minimizes the chance that you will have bleeding at the wrong time in the menstrual cycle and improves the likelihood that you won't forget your pill).
• Your package of birth control pills will either contain 21 or 28 pills. If you have a 28 pill package, the last 7 pills contain no medicine (placebo) and they are included simply to help you keep up the habit of taking your pills daily. If you have a 21 day package, you will take NO pills for 7 days between packages of the birth control pills. Menstrual bleeding should occur during this time. If you bleed at other times in the cycle or do not bleed during this 7 day period, notify your doctor.

Remember: Use an additional method of birth control for the first month that you take the birth control pills.

If you forget your pill, you should try to take it as soon as you remember it.

If you forget one pill (miss one day), take that pill and the pill you are suppose to take that day, together.

If you forget two pills (miss two days):

• if you are in the first 2 weeks of the package, then take 2 pills on the day you remember and two pills the next day. Then you will be caught up. Use a back-up form of birth control for 7 days following the missed pills.
• if you are in the third week of the package, continue 1 pill a day until the next Sunday, then discard the rest of the package and start a new package. A back-up method of birth control is necessary for 7 days following the missed pills.

If you miss three pills in a row, continue 1 pill a day until the next Sunday, then discard the remainder of the pack and start a new pack on that same Sunday. A back-up method of birth control is necessary for 7 days following the missed pills.