Bayer AG has recovered over 99% of unused Essure birth control devices that were to be pulled from the U.S. market in 2018 amid reports of serious health risks to women who received the devices, the U.S. Food and Drug Administration said in a Jan. 10 update.

Jeff Shuren, director of the FDA's Center for Devices and Radiological Health, said monitoring women with Essure devices continues to be a top priority for the agency, and the devices will no longer be available for implantation in the U.S. Bayer is actively seeking 10 remaining unused devices, Shuren said.

Essure is associated with serious health risks including persistent pain, bleeding of the uterus and migration of the device's coils into the pelvis or abdomen.

The FDA first asked the German drugmaker to conduct a post-market trial for Essure in 2016. The U.S. regulator revised the study requirements in December 2018 to add blood testing of women enrolled during follow-up visits and extend the duration of the trial to five years from three. The enrollment period for the post-market study is complete, with 340 women choosing Essure instead of a surgical birth control option, the agency said.

Essure, approved in 2002 as a permanent birth control device for women, can be implanted without requiring a surgical incision.