Women can rely on their Mirena intrauterine device to prevent pregnancy for up to eight years, the medicines regulator has decided, making it the longest-acting hormonal contraceptive available in Australia.
The Therapeutic Goods Administration’s decision includes existing devices.
The TGA issued the approval on 5 June based on data submitted by Bayer, which developed the device, from their Phase 3 Mirena Extension Trial, which showed efficacy remained above 99% during years six to eight among the 362 women studied.
A TGA spokesperson said the study “showed efficacy was maintained and revealed no new or unexpected safety issues”.
The Mirena IUD is inserted into the uterus where it slowly releases progestogen, which prevents pregnancy by thinning the lining of the uterus so that it is not thick enough for the woman to become pregnant and thickens the mucus in the cervix to prevent sperm from reaching an egg.
Peak bodies the Royal Australian College of General Practitioners and the Royal Australian and New Zealand College of Obstetricians and Gynaecologists welcomed the TGA’s decision, which they said aligns with the evidence.
The chair of RACGP’s Sexual Health Medicine group, Dr Sara Whitburn, said the “exciting news” of Mirena’s increased duration supports more women to choose this option. Despite being one of the most effective methods of contraception, rates of uptake in Australia remain low, with the contraceptive pill remaining the default.
“It makes the Mirena more cost-effective as the upfront costs of insertion are now spread over those years,” Whitburn said.
The cost of the Mirena device itself, subsidised by the Pharmaceutical Benefits Scheme, is about $31.60, but patients may also have to pay out-of-pocket costs for a general practitioner or gynaecologist to insert the device.
The chair of RANZCOG’s sexual reproductive health committee, Prof Kirsten Black, said “even with out of pocket expenses for IUD insertion, it’s still cheaper for the woman than buying the contraceptive pill over eight years, and cheaper for the health system because you’re going to prevent a whole lot of unexpected pregnancies, Black said.
“You are 20 times less likely to have an unintended [pregnancy] using an IUD compared to the pill,” Black said.
The pill also has a rate of efficacy above 99% if taken correctly, but because its effectiveness can be reduced if taken irregularly, or absorption can be affected by diarrhoea and vomiting. Nearly one in 10 women taking it may still get pregnant, according to the Royal Women’s hospital.
While recent data shows increasing rates of younger women using hormonal iUDs, the latest national data still showed rates of use in Australia are below 10%, Black said.
“To increase uptake of IUDs however we still need to improve access. This means having more healthcare professionals trained and prepared to insert IUDs.”
Whitburn said if a woman’s doctor told her to come back in five years for removal before the advice was updated, she can now wait eight years if the Mirena was inserted for contraception and menstrual control and she is under 45 years old.
The US regulator approved eight-year use for contraception shortly after the Bayer study was released in 2022 and the UK’s regulator approved it in January.
The TGA approval for extended use is for contraception only, all other uses including assisting heavy bleeding during periods or menopause hormonal therapy remain unchanged.
