Updated with comment from Bayer

The FDA today said it would put a pair of measures in place for the controversial Essure permanent contraception device made by Bayer (ETR:BAYN), mandating a new clinical study and new guidance on using the device.

Essure is a small metal coil that’s placed in the fallopian tubes via catheter. The FDA said last year that in the 13 years since Essure’s approval, the agency had received 5,093 complaints, including for pain or menstrual irregularities after using the device, and complaints of the device breaking. In addition to 5 fetal deaths, there were 4 reports of adult deaths for reasons such as infection and uterine perforation, the FDA said.

Earlier this month an analyst who examined the FDA’s adverse events website for cases involving the Essure device said the federal safety watchdog likely underestimated the number of fetal deaths linked to the implant.

Today the FDA said it would require Bayer to run a new trial designed to “determine heightened risks for particular women” and draft guidance including a boxed warning label explaining the potential for adverse events connected with Essure. Bayer must design and conduct the post-market surveillance study comparing Essure with laparoscopic tubal ligation, the FDA said, using measures such as rates of complications including unplanned pregnancy, pelvic pain and other symptoms, explantation surgery and an evaluation of the complications’ impact on quality of life.

“The actions we are taking today will encourage important conversations between women and their doctors to help patients make more informed decisions about whether or not Essure is right for them,” Dr. William Maisel, deputy director for science and chief scientist at the FDA’s Center for Devices & Radiological Health, said in prepared remarks. “They also reflect our recognition that more rigorous research is needed to better understand if certain women are at heightened risk of complications.”

The new draft guidance will also recommend a so-called “patient decision checklist” for physicians to discuss with patients “to better communicate risks and help to ensure an informed decision-making process,” the federal safety watchdog said. The agency is also recommending that patients implanted with Essure undergo a confirmation test 3 months after implantation to make sure that the scar tissue has enveloped the devices, ensuring that no eggs can pass through the fallopian tubes. The post-market study must also examine why some patients aren’t given the confirmation test at 3 months, the FDA said.

In a press release posted today, Bayer said that Essure was still an important permanent birth control option with a positive benefit-risk profile.  The company said that it will continue to work with the FDA to support continued safe, effective and appropriate use of the device.

“Patient safety and appropriate use of Essure are our greatest priorities. A woman’s decision to choose a birth control method is a very important and personal one, and Bayer is committed to providing physicians with resources, tools and information to help them counsel women about Essure,” Bayer Americas senior veep of medical affairs  Dr. Dario Mirski said in a prepared statement.

In a report issued before a September 2015 meeting of the FDA’s Obstetrics & Gynecology Devices advisory panel, the agency said it logged a nearly 1,400% spike in complaints filed over Essure in the last 3 years. During the hearing, Bayer’s director of global pharmacovigilance risk management, Dr. Andrea Machlitt, told the panel that the company received 17,000 adverse event reports, 15,000 from the U.S. The panel voted to recommend limited use of Essure until more is known about its safety.

In October 2015 a study found that women implanted with Essure were more than 10 times more likely to require post-procedure surgery than those who underwent laparoscopic sterilization.

A bill sponsored last year by Rep. Mike Fitzpatrick (R-Pa.) would ban U.S. sales of Essure altogether.