What’s the Least Effective Contraceptive?

(Photo: Getty Images/Science Photo Library)

By Laura Delamare

When choosing a contraceptive method, it’s good to be picky. Not all methods offer protection from sexually transmitted infections, and some offer better protection against pregnancy than others. To help make the choice, HealthGrove examined contraceptive data to see which methods are the least effective.

Using the most recent data from the Center for Disease Control and Prevention (CDC), HealthGrove crunched the numbers to find out which contraceptive methods have the highest failure rates for both perfect use and typical use. “Perfect Use” is the theoretical effectiveness of a contraceptive. “Typical Use” is defined by the CDC as a more realistic success rate—to account for mistakes, inconsistencies, and laziness in use of contraceptives. In this case, “failure” is determined by the percent of women experiencing an unintended pregnancy within the first year of typical and perfect use. The graph below highlights what that HealthGrove found, and the results might surprise you:

Spermicide is the contraceptive method that is most likely to fail. Spermicide is a foam, cream, jelly, film, or tablet that is inserted into the vagina to prevent sperm from moving. Spermicide is always used in conjunction with a diaphragm or cervical cap, but can also be doubled up with other contraceptive methods. With typical use, spermicide has a 29% failure rate in protection from pregnancy, and it also has a number of side effects including allergic reactions, irritation, and urinary tract infections. If it’s all you have, by all means, use it—but this contraceptive method certainly deserves its place at the bottom of the list.

The ovulation method, right in the middle of the graph, has a 25% failure rate with typical use. With this method, also known as the Billings Ovulation Method (BOM), women monitor their fertility during each menstrual cycle by observing their vaginal discharge each day. When women experience vaginal discharge and mucus, it can be a sign of ovulation, which is the part of the cycle when women can become pregnant. This method is free, and causes no side effects, but unfortunately has a 1 in 4 failure rate for typical users.

Here’s the shocker: condoms are are not as effective as many are led to believe. A popular, convenient, and widely available form of birth control, male condoms protect against both STIs and pregnancy, but only when used correctly. They are essentially latex or polyurethane covers that are placed over the erect penis to stop any sperm from entering the vagina. They are easy to use, cheap, and available—but still have an 18% failure rate with typical use. The lesson here is check the expiration date, store them in a cool, dry place, and be careful when applying.

If you are wondering, “then what contraceptives do work?” see the options listed in the widget below. HealthGrove has highlighted the six most effective contraceptive methods: the pill, the patch, the intrauterine device, the implantable rod, male sterilization, and everyone’s favorite: abstinence.