Over half of American women who get pregnant did not plan or want to have a baby at the time. If you don't have sexual intercourse, you can avoid this situation. However, if you do choose to have sex, the correct use of contraception (birth control) will greatly reduce the risk of an unplanned pregnancy. There are several methods of contraception:

• Natural Family Planning (NFP): Couples can use NFP techniques like the rhythm method, basal body temperature, or the cervical mucus method to try to pinpoint when a woman is ovulating (fertile). To prevent pregnancy, sexual intercourse is avoided around the time of ovulation.

• Chemical methods: Spermicide contains nonoxynol 9, a chemical that can be inserted into the vagina before intercourse to kill sperm. Spermicide comes in many different forms including creams, jellies, foams, suppositories, and contraceptive film. Spermicide is most effective when used with a barrier method.

• Barrier methods: Barrier methods prevent pregnancy by putting a physical "wall" between the sperm and the cervix (the entryway to reach the egg). Condoms, diaphragms, cervical caps, and female condoms are all barrier methods. They are most effective when used with spermicide.

• Hormonal methods: Birth control pills, contraceptive implants (Norplant), and contraceptive injections (Depo-Provera) contain hormones that prevent pregnancy by stopping ovulation, making it impossible for a fertilized egg to implant in the uterus, or making it difficult for sperm to enter the cervix.

• Intrauterine device (IUD): An IUD is a small device (containing copper or a hormone) that is inserted and left inside the uterus. It can prevent fertilization, or make it difficult for a fertilized egg to implant in the uterus.

There are a number of things to consider. You need to know how well each method prevents pregnancy. The table below shows how many women (out of 100) would still get pregnant if they were using the following birth control methods for one year (the lower the number, the more effective the method):

* Rates vary between specific contraceptive methods.

• How much money will the method cost?
• Will you and your partner be comfortable using the method? Is it convenient?
• Does the method have any side-effects? Can it be dangerous for certain people?
• Does the method provide any protection against sexually transmitted diseases?

Consult your doctor for more information to help you with your decision.