Long-acting contraceptives are 20 times more effective than shorter-acting methods, according to a New England Journal of Medicine study.

Nearly 7500 U.S. women at risk for unintended pregnancy were counseled about various reversible contraceptive methods, with a special emphasis on the lower failure rates with the two long-acting reversible methods: intrauterine devices and subdermal implants. The women were then allowed to choose any contraceptive method to use at no cost for up to 3 years.

Overall, there were 334 unintended pregnancies. In age-adjusted analyses, pregnancy risk was significantly higher among women using birth control pills, the patch, or the ring than among those using IUDs or implants (hazard ratio, 21.8). Participants under age 21 who used short-acting contraceptives had nearly twice the pregnancy risk as older participants using the same methods, while risk did not differ between age groups for long-acting contraceptives.

Dr. Eleanor Bimla Schwarz of Journal Watch Women’s Health commented: “These findings highlight the need to ensure that young women are informed about and have access to IUDs and contraceptive implants.”

Source: NEJM