(Photo: David Brandon Geeting)

After decades out of favor, the intrauterine device is making a comeback. This small, T-shaped form of birth control, which is placed in a woman’s uterus and prevents pregnancy for between three and 10 years, has carried a stigma in the United States ever since the 1970s, when one notoriously flawed model, the Dalkon Shield, caused septic miscarriages and infertility in thousands of American women. But now, health-care providers are trumpeting the safety—and efficacy—of the models currently on the market. The American College of Obstetricians and Gynecologists concluded as early as 2005 that IUDs and hormonal implants (which are inserted in a woman’s arm) are the most reliable forms of birth control, and should be among the top options offered to all women; the American Academy of Pediatrics released a similar recommendation in 2014.

Public health officials have good reason to be excited. Unlike more popular types of birth control—condoms and pills, the patch and the ring—these long-acting devices don’t require women and girls to fill a prescription, or to bring along protection every time they have sex. Accordingly, these devices are far more effective at preventing pregnancy. IUDs fail less than one percent of the time. The benefits of widespread adoption are potentially huge: When a privately funded experiment made IUDs and implants available for free across the state of Colorado, both the teen birth rate and the abortion rate dropped by about 40 percent.

Despite some recent buzz about long-acting birth control, though, only about nine percent of American women are actually using IUDs or implants—and perhaps only 50 percent have even heard of them. Here are five studies that explain why public health experts are so committed to driving those numbers up—and what needs to happen for them to succeed.

WOMEN WHO USE LONG-ACTING BIRTH CONTROL ARE MORE LIKELY TO STICK WITH IT, AND LESS LIKELY TO GET PREGNANT

In 2007, four researchers at Washington University in St. Louis set out to assess the information gap: If teens and young women were educated about long-acting birth control, would they want it? And if they got it, would they like it? The researchers offered free birth control to over 9,000 14- to 45-year-olds, counseling them on a host of options—including IUDs and implants as well as the patch, the ring, and the pill—by starting with the most effective methods and proceeding in order of reliability. After the counseling, 75 percent of the participants chose implants and IUDs. A year later, 86 percent of the women who’d chosen a long-acting method were still using it, compared with only 55 percent of those using one of the other methods. Pill, patch, and ring users were 22 times more likely to have an unintended pregnancy in the first year of the study than IUD and implant users.

—“The Contraceptive CHOICE Project Round Up: What We Did and What We Learned,” McNicholas, C., et al., Clinical Obstetrics and Gynecology, 2014.

IUDS MAKE "NOT-PREGNANT" THE DEFAULT, EVEN FOR PEOPLE WHO FEEL AMBIVALENT ABOUT PARENTHOOD

We classify pregnancy as either unintended or intended, but most people’s feelings fall in between. In a survey of 774 18- to 29-year-olds, 45 percent were ambivalent about pregnancy—and, among men, this ambivalence lowered the likelihood of contraceptive use. Isabel V. Sawhill of the Brookings Institution has argued that long-acting birth control is our best hope for changing a culture in which only about half of American pregnancies are planned, with many women "drifting" into motherhood. Because a woman with an IUD will have a hard time getting pregnant, long-acting birth control, in Sawhill's parlance, turns drifters into planners.

—“Pregnancy Ambivalence and Contraceptive Use Among Young Adults in the United States,” Higgins, J.A., et al., Perspectives on Sexual and Reproductive Health, 2012; Generation Unbound: Drifting Into Sex and Parenthood Without Marriage. Sawhill, Isabel V., Brookings Institution Press, 2014.

DOCTORS' TRAINING POSES ONE OF THE BIGGEST OBSTACLES TO WIDESPREAD USE

The biggest reason that so few women use long-acting birth control may be that many health-care providers don’t offer it. In part, this is because of outdated safety concerns among doctors who remember the Dalkon Shield all too well. It’s also at least partially tied to price: Long-acting birth control methods, which can cost women up to $1,000, are sometimes too expensive for clinics to stock. But a lack of training among physicians has proven an equally difficult barrier. A 2012 study found that nearly one-third of family health-care providers needed new training to insert an IUD before they’d feel comfortable recommending one, and about a third of both family doctors and obstetrician-gynecologists needed training in how to insert a hormonal implant. Overall, the study found, less than half of family doctors were talking to their patients about long-acting birth control.

—“Evidence-Based IUD Practice: Family Physicians and Obstetrician-Gynecologists,” Harper, Cynthia C., et al., Family Medicine, 2012.

A CULTURE OF MISINFORMATION POSES A PROBLEM, TOO

This year, a study of social influences on birth control usage found something disturbing: When researchers listened in on contraceptive counseling visits, they found that the majority of stories women had heard about birth control were negative. Teens, in particular, were coming into doctors’ offices with reports of adverse reactions and dangerous side effects. The IUD was the method their grapevine seemed to be buzzing about the most—and while some of that buzz was positive, nearly twice as much was cautionary. The researchers also found that most health-care providers did an inadequate job of talking patients through their fears and combating misinformation with facts.

—“Bringing Patients’ Social Context Into the Examination Room: An Investigation of the Discussion of Social Influence During Contraceptive Counseling,” Levy, K. et al., Women’s Health Issues, 2015.

THOUGH IUDS AND IMPLANTS ARE THE BEST OPTIONS FOR MANY, PRESSURING WOMEN TO USE THEM COULD BACKFIRE

Presenting birth control options in order of effectiveness can encourage women to choose the most fail-proof route. But pressuring a patient to pick one particular method can have the opposite effect. Studies show that low-income women and women of color are especially sensitive to signs that a doctor is trying to control their fertility. Women who suspected this kind of reproductive meddling were less likely to use contraceptives that required sign-off from a health-care provider. No matter how many public health benefits may attend the use of long-acting birth control, for women, the choice must ultimately be a private one.

—“Conspiracy Beliefs About Birth Control: Barriers to Pregnancy Prevention Among African Americans of Reproductive Age,” Thorburn, S. and Bogart, L.M., Health Education & Behavior, 2005; “Norplant Selection and Satisfaction Among Low-Income Women,” Clarke, L.L. et al., American Journal of Public Health, 1998.

Five Studies is Pacific Standard’s biweekly column that identifies and analyzes the best academic research to deliver new insights on human behavior.

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