Women report contraceptive implant failures

Editor's note: This article was updated after publication to include a statement from the manufacturer.

5^th January 2011 - Hundreds of women have become pregnant, despite using a popular contraceptive implant, according to figures from a health watchdog. They also show that hundreds more have complained of adverse reactions to the Implanon device, which first came into use 11 years ago.

The contraceptive implant is designed to stop women getting pregnant by releasing etonogestrel - a synthetic progestogen - into the bloodstream. The hormone is preloaded into a small tube which is inserted beneath the skin of the arm under local anaesthetic. The implant can be inserted by a trained GP or nurse and is designed to work for three years.

Nearly 600 pregnancies

The Medicines and Healthcare products Regulatory Agency (MHRA) says it has been told of 584 women using the Implanon device becoming pregnant since 1999. In total, it has received reports of 1,607 women having adverse reactions to the device.

The MHRA says that, out of the total number of unwanted pregnancies, there were nine reports of either device failure, device dislocation, the device being ineffective, or difficulty in using the implant.

Channel 4 News has reported that the NHS has paid out nearly £200,000 in compensation to women who have become pregnant or been injured by the implant. It featured an interview with a woman called Lara from south London who became pregnant when the device was incorrectly fitted. "This is not what I want,” she told the programme. “I put this thing in to protect myself so I can continue with my studies. I don't want kids at this time. It really disturbed me."

Lara said her marriage collapsed and she suffered nightmares for months after having an abortion.

Implanon is being superseded by a new device called Nexplanon. However, in October GPs and nurses were told that they could continue to fit Implanon until stocks ran out.

MSD, the makers of Implanon, said they were “confident in the efficacy and safety” of the implant. In an emailed statement a spokesperson said: “Since its initial approval in September, 1999 over 1.3 million units have been prescribed in the UK. Although no contraceptive is 100% effective, Implanon is more than 99% effective. A review of nine years of data has indicated 0.049 pregnancies per 100 implants sold (i.e. five per 10,000).”

Was there a problem with the insertion of Implanon?

The MHRA says there have been some reports of difficulties with both inserting and removing the device.  In an emailed statement, it says the implants come with detailed instructions for insertion as well as methods of reducing the risk of incorrect insertion or difficult removals.

It says the patient information leaflet warns of possible pregnancy if Implanon is not inserted correctly or was not inserted at all.