Three Democratic members of Congress have demanded a meeting with U.S. Food and Drug Administration officials over what they described in a Monday letter as the agency’s “inaction on the dangerous medical device Essure.”

In a recent investigation in collaboration with the Washington Post Magazine and Reveal, Investigative Fund reporter Jennifer Block found that while the FDA approved Essure as a safe, minimally invasive contraceptive device in 2002, thousands of women are now coming forward with serious side effects that may stem from its use.

Essure, a device produced by Bayer that represents the only permanent, non-surgical form of contraception, is no longer available for purchase anywhere in the world except for the United States following increased regulatory scrutiny in Brazil, Australia, and the European Union.

The FDA is monitoring the device’s safety and efficacy, and has ordered Bayer to conduct an additional study on the side effects of the device. In November, the FDA also issued a boxed warning for Essure about possible side effects.

But such steps have not assuaged the concerns of the lawmakers, who accused the FDA of allowing Bayer to “drag its feet on this post-market study while women are continuing to suffer.”

According to lawmakers, only one patient has been enrolled by Bayer into the company’s study despite its plan to enroll dozens of patients per month over the preceding year.

Update (11/13/2017): Bayer issued a statement to ABC 8 News in Richmond, VA, defending its commitment to the FDA’s post-market study against “baseless statements” in the Congress members’ letter. “In fact, Bayer has met every milestone, and even began enrolling subjects into the study three weeks early, the statement reads. The Congresswomen’s statement that ‘only one patient has been enrolled’ is simply incorrect.”