Intra-uterine devices (IUD's) remain the most popular method of reversible birth control worldwide, with up 85 to 100 million female users around the globe. This is in huge contrast to the rates in the United States, where the IUD is used only by about 1 million women (<1%), mostly due to patient and doctor fears over safety sparked by a device called the Dalkon's Shield in the 1970's. The device was equipped with hollow, multi-filament removal strings which were found to wick STI pathogens and bacteria deeper into the reproductive tract, causing severe infections like pelvic inflammatory disease that lead to infertility, and even death. It was pulled off the market, but fears remain decades later.
Today's IUDs are equipped with single-filament strings that have been rigorously tested to ensure they do not contribute to bacteria mobilization, and a recent study has found that while STI transmission rates were high in the study group -- due mostly to the high incidences of previous sexually transmitted genital infection --, the IUD caused no increased risk of pelvic inflammatory disease versus those who were not using the device. This implies the IUD is an excellent choice for women who desire very effective, reversible birth control but had previously been deemed too high-risk to have one inserted.
This is very good news on the front of non-hormonal birth control advancement. Many female-controlled methods of non-hormonal, reversible contraception have failure rates deemed unacceptably low to many women, as opposed to the copper-T IUD's failure rate of 0.6%, which puts it about equivalent to female sterilization with complete reversibility. Also, it is the most cost-effective method of birth control available for long-term use; the Mirena system (which contains trace amounts of levonorgestrel, believed to increase contraceptive effectiveness as well as decrease abnormal/heavy bleeding) has a life of about 5 years, while the copper-T lasts up to 10.
It is an acceptable choice for teen women as well -- adolescents' schedules can be especially hectic, which can make daily hormonal options formidable; some would like to avoid hormones altogether, but are nervous about the high failure rates of female-controlled barriers. Many physicians are receptive to inserting IUD's in young women who have never been pregnant so long as her uterus is large enough to accommodate the device and she is aware of the increased risk of explusion, perforation, increased pain during insertion, and the importance of remaining STI-free. Many will only insert the device once assured a young female is in a stable, monogamous partnership, and usually only if the teen herself asks about it as an option and seems well-educated about the risks and drawbacks.
However, just as many providers believe that teen women are incapable of protecting themselves against sexually transmitted infection, even with adequate information on prevention. Perhaps with this new information showing little increased risk of PID and other STI complications even in high-risk women, talks between a patient and physician can focus on a woman's contraceptive needs and the pros and cons of a chosen method above assumptions about her lifestyle!