Informing women about best choices for family planning

A surprising number of women overestimate the effectiveness of widely-used forms of contraception, according to a new study from the Washington University School of Medicine in St. Louis.

In order to determine the perceived effectiveness of various contraceptive methods, researchers surveyed over 4,000 women in the St. Louis area on their perceptions before they received counseling. The results, published in the American Journal of Obstetrics and Gynecology, indicate that nearly half of these women overestimated how effective the birth control pill and condoms are for protecting against pregnancy. (The polled women also overestimated the effectiveness of other methods: vaginal rings, hormonal patches, and injections.)

These results are especially concerning because, while pills and condoms are the most popular forms of reversible birth control in the U.S., the most effective forms of contraception are actually intrauterine devices (IUDs) and contraceptive implants a fact that many women are unaware of. An IUD is inserted into the uterus and releases small amounts of either copper or the hormone progestin, while the contraceptive implant is inserted under the skin in the arm and slowly releases small amounts of progestin. Both the IUD and the implant are highly effective at preventing pregnancy for several years (three for the implant, five for the hormonal IUD, and ten for the copper IUD), and all of these options provide protection to a woman without the constant vigilance that is necessary when relying on pills or condoms for birth control.

In fact, the risk of unplanned pregnancy is less than one percent for women using an IUD for a year, and the rate is only 0.05 percent (one in 2,000) for those with a contraceptive implant. In contrast, about 9 percent of women will experience an unplanned pregnancy in a given year with typical use of contraceptive pills. That figure rises to about 18 to 21 percent of women who rely on condoms as their primary form of contraception.

Despite the excellent record of reliability and safety of IUDs and implants, only about 5 percent of U.S. women who use contraception choose either of these. However, the study authors suggest that many more women might select these highly effective options if they were more fully informed about the relative risks and benefits of all of their contraceptive options. Case in point: After receiving counseling on their various birth control options, 71 percent of participants chose an IUD or implant.

Yet barriers to promoting effective contraceptive choices may extend beyond a woman s lack of awareness, points out ACSH s Dr. Gilbert Ross. Even many doctors aren t necessarily aware of the effectiveness and benefits of all of the different birth control options, he says. For example, many doctors still don t know that an IUD is appropriate and safe for women who have not yet had children. If a doctor does not have a complete understanding of contraceptive options, she or he can t appropriately counsel patients.