In The Know Zone

avoiding pregnancy

Avoiding Unwanted Pregnancy

There are a number of contraceptive strategies available to today’s teens.  There are two issues to take into consideration when choosing an approach—the failure rate of the approach and the degree of protection it offers against sexually transmitted diseases.

The failure rate of a birth control method is the percent of females who become pregnant while using it.  That includes pregnancies the method could not prevent, even if used properly, and those resulting from failure to use the technique correctly and consistently (generally a much higher figure). Condoms, for instance, only tear or slip about two to three percent of the time.  But the failure rate for condom use is typically about 14 percent.

In declining order of effectiveness, they are:

  • Abstinence: Abstaining from sex is certain to prevent pregnancy.  That’s the option chosen by most teens today. Only 46 percent of teenage boys and 47 percent of girls surveyed in 2002 said they were sexually active. [24] Failure rate: 0. [25]
  • Birth control shot (Depo-Provera). A hormone shot administered every three months by a doctor.  Used by about 10 percent of teens. Failure rate: Less than three percent, if shot is administered on time.
  • Birth control pills. Pills taken by the girl most days of the month. They contain hormones that prevent the release of the egg from the ovaries.  Requires a physical exam and a doctor’s prescription.  Used by 44 percent of teens. Failure rate: about five percent.
  • Condoms. A thin latex sheath worn over the penis during sex to keep sperm from being deposited. Used by about 37 percent of teens [26] . The only method that also provides protection against sexually transmitted diseases (STDs).  Widely available, cheap and easy to use.  One-year failure rate among teenage users is 14 to 50 percent because of inconsistent use.
  • Emergency contraceptive pill (ECP). A hormone pill designed to prevent pregnancy when administered within 72 hours following intercourse.  Usually prescribed by a doctor.  Failure rate: about 25 percent.
  • Rhythm method. Attempting to avoid pregnancy by not having sex during the period in which the egg is released from the ovaries.  Failure rate: about 25 percent.
  • Withdrawal. The male withdraws his penis prior to the release of sperm during ejaculation. Used by about four percent of teens, despite a high failure rate of about 27 percent.
  • Spermicide. Creams, gels, foams and suppositories inserted into the vagina to kill sperm before they can reach the uterus.  Must be applied 15 minutes or less before intercourse. Widely available and require no prescription.  Failure rate: 29 percent.  .
  • Douching. Squirting a chemical, often mixed with water, into the vagina to flush out sperm following intercourse.  Not a true birth control method. Failure rate: about 40 percent.
  • Hormone-releasing skin patches: A new technology.   Requires a doctor’s prescription.  No independent figures regarding failure rate are available.
  • Intrauterine device (IUD): A plastic insert, sometimes coated with the hormone progesterone, which is placed inside the uterus.  A doctor must insert and remove it. Not recommended for teens and women who have not had a baby.
  • Diaphragms, cervical caps, spermicidal sponges. Rarely used by teens, Diaphragms and cervical caps must be fitted by a doctor. Failure rates: 15-16 percent for cervical caps and diaphragms, 19 percent for sponges.  Sponges were withdrawn from U.S. market in 1995.  Still sold in Canada. [27]

[24] Abma, J., Martinez, G., et. al., Teenagers in the United States: Sexual Activity, Contraceptive Use and Childbearing 2002, National Center for Health Statistics,  December 2004, p. 2,. Available at, Accessed 12/27/2004

[25] One small qualification is in order.  There is a very slight chance of pregnancy if semen is inadvertently introduced into the girl’s vagina during certain sexual practices that approach but stop short of penetration.

[26] Use rates include married teens and apply only to the 72-84 percent of sexually active teens who use contraception..

[27] Above descriptions and failure rates adapted from  Dowshen, S, Macones, G. and Izenberg, N., Birth Contol: What You Need to Know, The Nemours Foundation,  2003, available at Accessed 12/15/2004


In The Know: At Risk Pamphlet/ DVD Package
In The Know: At Risk DVD Package