Brazil has lifted a ban on the sale of Essure female sterilization implants after receiving results from clinical trials on its risks, authorities said Tuesday.

Sale of the implants, which was suspended in February, was authorized after its maker Bayer presented documents detailing test results that had been sought by the Brazilian Health Regulatory Agency (Anvisa).

These included results of clinical trials that lasted a year or longer as well as a report on measures taken by the maker after a warning by Canada's health agency.

The so-called "permanent birth control" method involves the implantation of a metal coil in each fallopian tube which leads to the build-up of scar tissue that forms a barrier preventing sperm from reaching eggs.

Acquired by German pharmaceutical firm Bayer in 2013, its use is being scrutinized by a number of countries, including the United States and France since 2015 following a surge of complaints about side effects.

About one million units have been sold worldwide since 2001.

Anvisa said its earlier suspension was brought about by the company's failure to respond to concerns on the product's safety.

Side effects can include changes to the menstrual cycle, unwanted pregnancies, chronic pain, perforations of the uterus and fallopian tubes, migration of the device to the abdominal or pelvic cavity and suspected allergic or hypersensitivity reactions.

A collective lawsuit against Bayer is set to be filed in France in September by a group of 400 women, a lawyer representing them told AFP, while a Facebook group called "Essure Problems" currently counts more than 33,000 members.

Source: AFP