Those past concerns might stem from the Dalkon Shield debacle of the 1970s, when multiple users of that IUD reported experiencing serious medical problems—inflammation, infection, and even infertility. That shadow loomed large in U.S. consciousness for a while, Quartz reported last year: "Many patients—and even physicians—are still under the impression that all IUDs put women at risk for infertility, ectopic pregnancy, and perforation of the uterus," author Rachel Feltman wrote.

"Currently available IUDs are safe and effective for women, including teens," Tara Jatlaoui, an OB-GYN and guest researcher in the CDC’s Division of Reproductive Health, said in an email. "While many IUDs of the past were also safe, the Dalkon Shield tainted the IUD's reputation and was pulled from the market in the 1970s due to serious complications with its use after a few short years. Current IUDs do not have the same design or insertion procedure as the Dalkon Shield, which contributed to an unacceptable number of complications with its use."

“IUDs are very different than they were in the 1970s,” says Lisa Romero, the lead author on the new report and a health scientist in CDC’s Division of Reproductive Health. “[Parents] may think about ‘the IUD I knew back when.’” She says she encourages parents to get educated, as well as teens. As well as providers. Education all around, actually, seems to be in order.

With the AAP and ACOG recommendations still being relatively new, IUDs and implants may not yet have saturated the public consciousness the way condoms and birth-control pills have.

“A lot of times teens go into a clinic and say ‘I want to get on the birth-control pill,’ because they’re not aware they can use a long-acting reversible method,” Romero says. If they did know they could, most of them would choose one. When the CHOICE project, conducted by Washington University in St. Louis, offered free contraception and counseling to 1,404 teens, 75 percent of them chose a LARC. And 86 percent of the LARC adopters were still using their method of choice a year later.

“Continuation rates are very high,” Romero affirms—probably because once the IUD or implant is inserted, that’s it. You don’t have to do anything else until it’s time to take it out three to 10 years later. But even when teens are fully informed, they may have concerns. Getting an IUD inserted is more invasive than just swallowing a pill, after all.

“They may be concerned about having a foreign object in one’s body, or about possible painful insertion or removal,” Romero says. “They may say ‘I’ve heard you bleed a lot at the beginning,’ or ‘I’m concerned you might be able to see or feel the implant in my arm.’”

The physician’s role in all this is as an informant—to let patients know what to expect and address misconceptions (you can’t feel or see an implant in your arm, for example, Romero says). Many adolescents still see pediatricians, though, and as Kaiser Health News reported earlier this year, pediatricians aren’t always sufficiently trained in inserting IUDs. And they may not be comfortable offering IUDs and implants as options to young women, since it’s likely that for most of the time they’ve been in practice, this wasn’t the official recommendation.