IUD usage is on the rise in U.S.

After two decades of being about as popular as chastity belts, the intrauterine device is catching on again in this country.

IUD use nearly tripled in just six years, growing from 2 percent of birth-control users in 2002 to about 6 percent in 2008, according to the latest federal survey. That translates to 2.1 million women - and the kind of market growth not seen since sales peaked in the 1970s.

Medical organizations and health activists are finally succeeding in debunking the idea that all IUDs are dangerous, a misconception rooted in the Dalkon Shield debacle of the 1970s. Clinicians are once again touting the method's hassle-free, long-acting, reversible benefits, while websites like IUD Divas let women share every cramp, question, and concern.

This is not to suggest the IUD is now free of controversy. Regulators have been cracking down on physicians who turn to Canada for cut-rate ParaGard and Mirena IUDs - the only two brands approved in the United States - as a way to save money.

Cost is the one obstacle to IUD use that has grown, not lessened. Bayer Healthcare Pharmaceuticals, which acquired market dominator Mirena in 2006, announced four months ago that it was raising the retail price to $843, an 80 percent increase.

"It's blatant corporate greed," said Jennifer Boulanger, executive director of the Allentown Women's Center, whose outraged letter to her Bayer sales rep was ignored.

Bayer spokeswoman Rose Talorico countered that even with the increase, Mirena is a bargain, given that it lasts for five years: "Mirena is significantly less than today's average monthly cost for hormonal contraceptives."

Many factors were behind the IUD's heyday in the 1970s, including the advent of flexible plastic, the sexual revolution, lax regulation of medical devices, and fear of the Pill's hormone-related bad effects.

But the force that stands out in the rise - and fall and rise - of the IUD is physicians.

Obstetrician-gynecologists invented many IUDs, including the Dalkon Shield, and initially sang the praises of the method, which interferes with the sperm and egg in ways that remain mysterious. At the high point, almost 10 percent, or 2.5 million, of U.S. women had IUDs.

Doctors also did much of the research that gave the IUD a bad rep and killed demand.

In the case of the Dalkon Shield, the scorn was earned. The multifilament string that let a woman check whether the device was in place turned out to be a ladder for infection-causing bacteria. By the time the shield was recalled in 1974 after three blockbuster years, it was linked to ectopic pregnancies, miscarriages, hysterectomies, infertility, even deaths.

In contrast, the studies that tarred other brands were unreliable.

"Flaws in early IUD research exaggerated the risk," Princeton University's James Trussell and coauthors wrote in their reference book, Contraceptive Technology.

Rigorous evaluations of contemporary IUDs show they don't increase the risk of ectopic pregnancy, pelvic infections, or infertility, and they rival sterilization for preventing pregnancy. Mirena's plastic T, which releases the hormone progestin, can also relieve heavy menstrual bleeding.

The main risks are that in one in 1,000 women, the IUD will puncture the uterine wall, usually during insertion. At least one in 50 women will expel the device.

Getting the good news out has not been easy. After doctors spurned the IUD, they clung to misperceptions about the risks. A 2002 study found that 9 out of 13 American medical texts incorrectly identified pelvic inflammatory disease as a risk of IUDs.

"Many doctors are still misinformed," said Margaret Baylson, a family physician who specializes in reproductive health at Penn Presbyterian Medical Center.

Indeed, a 2006 poll of family physicians in Kingston, a midsize Canadian city (not unlike midsize U.S. cities), found more than half considered the IUD dangerous, and most thought it was unsuitable for childless women.

Even OB-GYNs, who presumably should have known better, did not, according to a 2000 survey of OB-GYNs by University of North Carolina researchers. Twenty percent had not inserted an IUD in the last year, and the rest had inserted one 10 times or fewer.

"Fear of litigation and a belief that IUDs cause pelvic inflammatory disease" made them leery, the study found.

Slowly, though, the fear is subsiding as medical and reproductive-health associations promote the IUD through seminars, Web-based courses, and guidelines.

Three years ago, for example, the American College of Obstetricians and Gynecologists recommended that doctors "strongly encourage" IUD use by sexually active teenagers. Contrary to outdated thinking, teenagers' anatomy does not preclude an IUD.

"Teens are some of the best candidates for IUDs," Baylson said, because they don't have to remember to take or put on anything.

"In some cases," she added, "it's more challenging to insert the IUD. The cervix hasn't been dilated [by childbirth], so it's more tightly closed. But for those of us who have training in insertion, it's rarely a problem."

Teaching insertion has become part of marketing IUDs.

"We have a large initiative with ParaGard insertion-training programs," said Amy Nieman, head of women's health for Teva Pharmaceuticals, which has a plant in North Wales.

Planned Parenthood Southeastern Pennsylvania has seen the impact of bringing in trainers, said Mary Banecker, vice president for patient services. The number of patients opting for IUDs has grown from about 200 in 2006 to almost 900 last year.

The companies need clinicians to talk up the method, because direct-to-consumer advertising is as rare with IUDs as it is relentless with many other prescription products. Bayer has had a Mirena TV commercial for a couple of years, but another attempt to pitch directly to women barely got off the ground last year before it was dropped.

The company set up in-home parties (think Tupperware with more intimate chitchat) to tout Mirena as a way to improve romance, energy, even looks.

In December, the Food and Drug Administration sent a letter ordering Bayer to stop making false and misleading claims.

Despite the lack of ads, women are increasingly asking doctors about IUDs, emboldened by IUD Divas, Facebook cliques, YouTube, and other cyber confidantes. (Yes, disenchanted IUD users also have online communities.)

Rebecca Altman, 30, of West Philadelphia, a nurse practitioner pursuing a master's degree in public health, recently got a ParaGard after consulting girlfriends.

"I was interested in long-term contraception for some time," Altman said. "But with past physicians, they weren't interested in IUD placement because I'd never been pregnant."

Among college-educated contraceptive users such as Altman, the IUD is the method of choice of 7 percent, up from 2 percent in 2002, according to the government's National Survey of Family Growth. Among traditional fans - women with a couple of children - IUD ranks have reached 11 percent.

"It's exciting to me to know that all our hard work to reverse the mythology might actually be having an impact," said OB-GYN Courtney Schreiber, director of the University of Pennsylvania's family-planning fellowship program. "We're practically the only country where the IUD is underutilized."

And the only country where the gadgets cost so much.

ParaGard costs $400 to $500, and Mirena is $843 retail ($703 wholesale), not including doctors' services.

While economical for contraception lasting years (10 for ParaGard), that's a lot for a young woman without insurance to pay at once.

It's also a big up-front investment for physicians, who traditionally purchase and stock IUDs, making no money until the product sells - sort of like car dealers.

Recently, some physicians have cut corners by ordering IUDs from Canada, where the price is less than $300.

But in July, the FDA sent a letter to clinicians nationwide, warning that importation of "unapproved" and possibly fake IUDs "may be illegal." The letter was prompted after a Bayer sales rep tipped Rhode Island regulators, who told the FDA, that OB-GYN practices in that state were using imported IUDs.

Whether or not all this dampens the IUD revival, it is already making Mirena less readily accessible.

Boulanger, for one, said her Allentown clinic would no longer stock the product. "If a patient wants to bring us an IUD," she said, "we will insert it."

On the other coast, Stephen R. Wells, an OB-GYN in Walnut Creek, Calif., wrote his patients to explain why he wouldn't keep Mirena on hand - and suggested they consider getting it from Canada.

"I love the Mirena IUD and still feel it is an excellent choice," he wrote. "I am very disappointed with the decision Bayer made."