A US study has found that longer-acting forms of contraception are more effective than birth control pills in protecting women against unwanted pregnancies.
The research, conducted by the Washington University School of Medicine in St. Louis and published in New England Journal of Medicine, showed that women who use birth control pills, the patch or vaginal ring are 20 times more likely to have an unintended pregnancy than those who use an intrauterine device (IUD) or implant.
The study involved more than 7,500 women enrolled in the Contraceptive CHOICE project. Participants were ages 14-45 and at high risk of unintended pregnancy.
In the study, women aged under 21 who used short-term contraceptive methods were twice as likely to get pregnant unintentionally than older women.
Professor of Obstetrics and Gynecology Jeffrey Peipert said, "This study is the best evidence we have that long-acting reversible methods are far superior to the birth-control pill, patch and ring.
"IUDs and implants are more effective because women can forget about them after clinicians put the devices in place."
Statistics show that 50% of all pregnancies in the US are unplanned and past studies have shown that about half of these result from contraceptive failure.
IUDs and hormonal implants, however, can cost more than $500 and many women in the US can't afford them.
Lead author of the study Brooke Winner said, "We know that IUDs and implants have very low failure rates - less than 1%. But although IUDs are very effective and have been proven safe in women and adolescents, they only are chosen by 5.5% of women in the United States who use contraception."
Image: Women in the US are 20 times more likely to become pregnant unintentionally when using short-term contraceptive methods like the pill rather than implants and IUDs. Credit: Ceridwen