The review, published in the journal Contraception, found that the older a woman is when she has an IUD inserted, the longer the device remains effective. IUDs are the most-effective form of reversible contraception.
Among women who have had at least one child and are ages 25 and older at the time of insertion, copper IUDs can be effective for at least nine years, depending on the brand. For example, the copper IUD ParaGard, which is recommended for up to 10 years of use, can be effective for at least 12 years. For women ages 35 and older at the time of insertion, ParaGard can remain effective until menopause.
Meanwhile, Mirena, which is a plastic IUD that releases levonorgestrel hormones to prevent pregnancy, is advertised for up to five years of use, but it is effective for at least seven years, according to the review.
The review also included IUD models that are not approved or available in the U.S., with similar results. The researchers noted that there are too few studies on women under age 25 to conclude how long Mirena and ParaGard are effective beyond the recommended use in that age group.
Study co-author Justine Wu of the Rutgers Robert Wood Johnson Medical School said that while official recommendations for IUD use have remained the same for some time, the review's conclusions are not new information. She added that the researchers hope the "review will bolster clinician and patient confidence, both in the United States and worldwide, in the safety and benefits of extending use of certain IUDs beyond the manufacturer-approved time period, among select women."
Wu also noted that extended use of IUDs in women over age 25 who have had at least one child could improve convenience, reduce cost and extend contraceptive benefits. She said that there are anecdotal reports of a few practitioners already allowing extended use, although it is unusual.
Jeffery Peipert, who was not involved in the study but has studied IUDs at the Washington University School of Medicine, added that there are few risks to leaving an IUD inserted for an extended period of time, but he noted that the devices could be more difficult to remove after menopause (Doyle, Reuters, 3/13).