The hormone-releasing Mirena coil intrauterine device (IUD) is a better treatment for heavy menstrual periods than other conventional medical approaches, according to results of a major clinical trial led by scientists from the Universities of Nottingham and Birmingham.

The findings of the ECLIPSE study, funded by the National Institute for Health Research (NIHR), are expected to change standard clinical practice.

Heavy periods, or menorrhagia, affect the lives of many women aged 25-50, accounting for many GP consultations and 20% of gynaecological referrals in the UK. Yet there has been limited evidence to support informed choices about treatments.

The ECLIPSE trial compared the clinical effectiveness of the levonorgestrel-releasing intrauterine system (also known as LNG-IUS or the Mirena contraceptive coil) with other medical treatments on offer in primary care.

A total of 571 women, consulting their GPs for heavy menstrual bleeding, agreed to be randomly assigned to LNG-IUS or to another standard medical treatment, such as tranexamic acid, mefanamic acid, combined estrogen and progestogen or progestogen only.

Over two years, outcomes improved more with LNG-IUS than with other treatments, including women’s experience of social, family and work life, and psychological and physical health.

The research, published online in the New England Journal of Medicine, found women allocated to LNG-IUS were almost twice as likely to still be using it than those taking other medication after two years. Some 49% of other trial participants switched to LNG-IUS citing ‘lack of effectiveness’ of other treatments.

Joe Kai, a GP and Professor of Primary Care at The University of Nottingham, said: “We hope our results are very positive news for women and their GPs. This trial tells us not only that treatments can be effective, but also what to choose, bearing in mind a woman’s preferences for having a contraceptive IUS inserted or not.

“Heavy menstrual bleeding can be very debilitating but we know many do not seek help. We need to make women more aware beneficial treatments are available, and to offer options such as LNG-IUS more often.”

Janesh Gupta, Professor of Obstetrics and Gynaecology at the University of Birmingham and based at Birmingham Women’s Hospital, said: “While the interventions studied in this trial represent options available in primary care settings in the UK, insertion of IUDs is not part of primary care in all health care settings, and in some circumstances requires gynaecologist consultation. This trial should encourage the use of IUDs in primary care.”