A STERILISATION implant used on the NHS has attracted "serious" safety concerns from health experts.

The Essure device, manufactured by pharmaceutical giant Bayer, has already attracted huge controversy in the US after regulators received more than 5,000 complaints from women.

Two law firms in the UK, Leigh Day and Irwin Mitchell, now say they have been contacted by women who say their health has been negatively affected by the implant.

The Medical and Healthcare products Regulatory Agency (MHRA) said it could not disclose the number of reports it had received regarding Essure but it was aware of some problems among users.

It said it had no current information to suggest the Essure device was unsafe.

In a new study published in the British Medical Journal (BMJ), experts from Cornell University in New York said women who have the device have a 10 times higher risk of needing another operation.

They compared results for 8,048 patients undergoing sterilisation with Essure with 44,278 undergoing usual laparoscopic sterilisation.

They wrote: "At one year after surgery, hysteroscopic sterilisation (Essure) was ... associated with a substantially increased risk of re-operation compared with laparoscopic sterilisation."

The authors warned that this increased rate was a "serious safety concern".

The Food and Drug Administration (FDA) in the US is reviewing the benefits of Essure after it received thousands of reports about the device.

American campaigner Erin Brockovich has also been working in the US to raise awareness about what she considers to be the dangers of Essure.

Essure differs to more traditional sterilisation by blocking the fallopian tubes and is less invasive to have installed.

The implants are usually inserted under local anaesthetic. A narrow tube with a telescope at the end, called a hysteroscope, is passed through the woman's vagina and cervix.

A tiny piece of titanium metal is then put into the hysteroscope, then into each of the fallopian tubes.

The implant causes the fallopian tube to form scar tissue around it, which eventually blocks the tube.

A statement from the MHRA said: "We currently have no information to suggest that Essure devices used in the UK are unsafe to use.

"We keep all such devices under review and will consider this latest evidence and offer updated advice where appropriate."

FDA data shows in 482 cases, patients said the device had migrated to elsewhere in their body while 259 reported the device breaking.

Five reports involved the deaths of unborn babies in women who had become pregnant despite having Essure. Four deaths in women with the device were also reported.

A statement from Bayer said: "Essure is a highly effective birth control option with a positive benefit-risk profile for women who have completed their families and want permanent contraception with a non-surgical procedure.

"Over a decade of research and development and a decade of real world experience supports the safety and efficacy of Essure."

It said an Essure confirmation test is administered three months after the procedure to determine whether or not a woman's fallopian tubes are blocked.

This test "may detect unsatisfactory device placement, resulting in the need for 're-operation' to remove the device and/or complete a tubal ligation if sterilisation is still desired," the statement said.

"Because there is no confirmation test that could identify potential failure of a laparoscopic tubal ligation procedure, it stands to reason that the comparative re-operation rate would be lower."