3 Factors that Affect Birth Control Effectiveness

Whether you're on the pill, have an IUD, or use condoms, you need to be extra vigilant about your birth control method in order to maximize its effectiveness. Forgetting to take a pill or buying a cheap condom can result in an unwanted pregnancy.

"When you average out all types of birth control, there is about a 3 percent failure rate," says Jennifer Wu, MD, an obstetrician-gynecologist at Lenox Hill Hospital in New York City. "The reliability of any birth control depends upon the patient."

Here's what to consider when considering the effectiveness of your birth control method.

1. If you take birth control pills, ask your doctor if any other medications that you are taking could affect it,  says Carolyn Westhoff, MD., medical director of the Family Planning Clinic at NewYork-Presbyterian Hospital/Columbia in New York City. "Since certain prescription medications can interact with the pill, find out if you are on one that could make your pill not as effective," she says. "The main culprits are anti-epilepsy medications, but it's a good idea to check."

2. The birth control pill is 99 percent effective when taken properly, but missing the birth control pill makes it less reliable, Wu says. If you are on birth control pills, take your pill at the same time each day or night, Westhoff says. Since it's likely that you'll be on a different schedule on the weekends from during the week, plan for that. If you sleep late on weekends and have an irregular schedule, you may want to always take the pill when you brush your teeth. You may want to even program a "pill reminder" into your cell phone and give yourself a little beep when it's time to take the pill.

3. Keep in mind that the pill doesn't work for the first month you're taking it, so be sure to use an alternate method during that period.

3 Tips for Effective Use

1. Choose a method of birth control that you can live with. If you don't like the idea of a patch on your skin, don't use the patch, and if the whole idea of having an IUD inside of you is discomforting, or if your partner hates the feel of the little string from the IUD, consider alternate methods. "Every woman needs to pick the method that's right for her," says Millicent Comrie, MD, an obstetrician-gynecologist at Long Island College Hospital in New York City. "Your doctor should work with you to come up with the right birth control for you. It should be a method that both partners feel comfortable with."

2. If you use condoms, be sure to avoid buying cheap ones. They tend to break.

3. Withdrawal and the rhythm method of birth control often are not reliable. "With the withdrawal method, you are relying on your partner," Wu says. "To use the rhythm method, you must have a very regular menstrual cycle. Otherwise, it can really fail you."