MirenaThe largest study of its kind has shown while both Mirena and copper intrauterine devices both deliver low rates of uterine perforation, Mirena lowers rates of contraceptive failure by more than eight-fold.

The study, called the European Active Surveillance Study for Intrauterine Devices (EURAS-IUD), comprised over 61,000 women from six countries, including the UK making it the largest to date to document contraceptive efficacy, adverse events and potential risk factors for uterine perforation among IUC use.

Dr Dearbhla Hull, Head of Medical Advisory Women’s Health at Bayer HealthCare, said: "This is a large study, conducted in a real world setting, which shows that both types of IUC are effective options for women, with a more favourable benefit-risk profile towards Mirena than the Cu-IUD.

"Many women are often unaware of the different contraceptive options available to them. It is important that, as part of any contraceptive consultation, all methods including IUC - which are among the most effective reversible methods - are discussed to ensure women are making informed decisions about the best method for their needs.”

EURAS-IUD also highlighted low absolute rates of ectopic pregnancy in women and explored the risk factors associated with perforation. Of the 118 total pregnancies, 21 were ectopic with double (14) in the Cu-IUD group. By contrast of 81 cases of uterine perforation which occurred, the spread was even and 63 were associated with previously suspected risk factors including breastfeeding and limited time since last delivery (<36 weeks).

While absolute rates of perforation and ectopic pregnancy in women are low, they may impact future fertility so benefits and risk of use should be carefully evaluated and insertion should be carried out in line with the summary of product characteristics for each method.

To find out more visit www.ncbi.nlm.nih.gov./pubmed/25601352