(HealthDay News) – Long-acting reversible methods of contraception such as intrauterine devices (IUDs) or implants are more effective for preventing unintended pregnancy than oral contraceptive pills, transdermal patches, or contraceptive vaginal rings, regardless of the user’s age, according to a study published in the May 24 issue of the New England Journal of Medicine.

Brooke Winner, MD, from Washington University in St. Louis, and colleagues conducted a prospective study involving 7,486 participants who were provided with reversible contraception of their choice at no cost. The rates of failure were compared for long-acting reversible contraceptives and other commonly prescribed contraceptive methods.

The researchers noted 334 unintended pregnancies. Among users of contraceptive pills, transdermal patches, or vaginal rings, the contraceptive failure rate was 4.55 per 100 participant-years, compared to 0.27 among users of long-acting reversible contraception (adjusted hazard ratio [HR], 21.8). Participants younger than 21 years of age who used the pill, patch, or ring had a risk of unintended pregnancy that was almost twice as high as the risk seen in older participants. Regardless of age, rates of unintended pregnancy were similarly low among users of depot medroxyprogesterone acetate injection and users of IUD or implants.

“The effectiveness of long-acting reversible contraception is superior to that of contraceptive pills, patch, or ring and is not altered in adolescents and young women,” the authors write.

One author received compensation for consultation and expert testimony pertaining to vaginal rings; several authors disclosed financial ties to pharmaceutical and health care companies.

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