Women on birth-control pills, the vaginal ring or the patch have a 20-fold higher risk of becoming unintentionally pregnant compared to those on IUDs (intrauterine devices) or implants, i.e. longer-acting forms of birth control, researchers from Washington University School of Medicine in St. Louis reported in NEJM (New England Journal of Medicine).
Birth-control pills can be very effective, as long as there is excellent compliance, i.e. if the woman taking then remembers to do so every day.The authors found that short-term contraceptive methods, including birth-control pills, the ring or the patch were particularly unreliable among younger females – women aged under 21 years are twice as likely to become unintentionally pregnant compared to older ones.
The researchers believe that the number of unplanned pregnancies among adolescent females in the USA would drop significantly if more of them went onto longer-acting contractive methods.
