The Irish Medicines Board says it has received 32 unintended pregnancy-related reports associated with use of the contraception Implanon since the product was authorised in Ireland in 1999.

The IMB was reacting to news that nearly 600 women in the UK became pregnant despite being fitted with the implant.

The tube is inserted in the arm and releases hormones into the bloodstream. It is designed to prevent pregnancy for three years.

In a statement, the IMB said the risks of unintended pregnancy and effects associated with Implanon are well-known.

It said the risks are detailed in the product information for healthcare professionals and patients.

The IMB is advising any woman who has concerns about their contraception method to consult their doctor.

The UK's Medicines and Healthcare products Regulatory Agency (MHRA) confirmed it had received a total of 1,607 adverse drug reaction reports linked to Implanon, relating to 2,888 incidents of suspect reactions in users.

Nine of the 584 women who reported an unwanted pregnancy used the terms 'device failure', 'device dislocation', 'device ineffective' and 'device difficult to use' to describe their experience.

Other women reported scarring and problems with removing the 40mm long implant.

In a statement, manufacturers MSD said: 'MSD is confident in the efficacy and safety of Implanon, a contraceptive medicine that has been prescribed to women since its initial approval in September 1999.

'The basis for successful use of Implanon is a correct and carefully performed subdermal insertion of the implant in accordance with the product instructions.

'If the implant is not inserted in accordance with the instructions and on the correct day, this may result in an unintended pregnancy. In addition, no contraceptive is 100% effective.'