Researchers at the U.S. Centers for Disease Control and Prevention (CDC) surveyed almost 2,000 health care providers and found that nearly one-third either thought IUDs were unsafe for women who had never given birth or were unsure of their safety.

IUDs, or intrauterine devices, are implanted in the uterus, where they release small amounts of either copper or the hormone progestin to prevent pregnancy. When IUDs first came out, there were concerns that they might increase the risk of pelvic infection and jeopardize women's future fertility.

But it's now known that IUDs do not carry that risk, said Crystal Tyler at the CDC, who led the study. What's more, unlike condoms and birth control pills - both more popular in the United States - they are put in place and can be "forgotten."

"IUDs are safe for ... women" who have not given birth, said Tyler. "And IUDs are as effective as sterilization, but they're a reversible form of contraception."

The hormonal IUD, sold under the brand name Mirena, can prevent pregnancy for five years, while the copper version, sold as ParaGard, is effective for about 10 years.

A separate recent study found that 0.8 percent of U.S. women using a copper IUD had an unplanned pregnancy within a year, while the rate for those on the hormonal IUD was 0.2 percent.

By contrast, about nine of every 100 women on birth control pills can expect to have an unintentional pregnancy in a year, owing largely to imperfect use. With condoms, about two percent of women will become pregnant, but that's only if a couple uses them correctly every time they have sex.

Tyler and her colleagues, whose results are reported in Obstetrics and Gynecology, surveyed obstetrician/gynecologists and family doctors, as well as nurses and physician assistants working at family planning clinics.

Overall, about 30 percent thought the devices were unsafe for women who had never given birth or were unsure of their safety. Not surprisingly, they were also less likely to implant IUDs - six times more likely to say they "infrequently" implanted the devices in women who had never had a baby than compared to other providers.

But IUDs were not a popular form of contraception in general. More than 60 percent of all providers in the survey said they only occasionally provided them, often because of "patient preference."

"Unfortunately, the U.S. is a little behind other countries in IUD use," said Tyler. "Many women don't really know they're out there."

With more health-provider education, that could change, she added. Groups such as the American College of Obstetricians and Gynecologists (ACOG) say IUDs are highly effective and more women should be aware of that.

Like other contraceptives, IUDs can have unwanted side effects. The Mirena IUD may cause menstrual irregularities, but generally makes periods lighter and is also approved as a treatment for heavy bleeding.

The ParaGard IUD has the opposite effect: menstrual bleeding and cramping can increase, though that may go away over time. SOURCE: bit.ly/GY2BBP

(Reporting from New York by Amy Norton at Reuters Health; editing by Elaine Lies and Bob Tourtellotte)

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