Explainer: How do the Pharmac-funded contraceptives Mirena and Jaydess work?

Pharmac has announced it will fund two kinds of intrauterine devices (IUD) for all New Zealanders seeking long-term reversible contraception.

Mirena and Jaydess previously cost hundreds of dollars but will become freely available from November, a move welcomed by Family Planning.

"Funding these two additional devices for contraception will improve equity and access to health care," chief executive Jackie Edmond says.

"This is a great step forward for New Zealand - it’s something we have wanted for a very long time and we are delighted."

But what are the devices and how do they stack up against other forms of birth control?

What is an IUD? 


An IUD is a T-shaped device about the size of a large grape that sits inside the uterus to prevent eggs being fertilised. There are two different kinds: copper and hormonal. A copper IUD makes the uterus hostile to sperm and eggs, while a hormonal IUD releases progestogen which thins the uterine lining and thickens the cervical mucus to make it more difficult for sperm to reach the egg. There are many different brands of IUD available around the world. Mirena and Jaydess (a new brand) are both hormonal IUDs.

How effective is an IUD? 


Family Planning considers an IUD 99 percent effective at preventing pregnancy, mostly because - unlike condoms or the pill - you don't have to think about it once it's inserted. 

In contrast, condoms are estimated to be 98 percent effective at preventing pregnancy on their own, but that number drops to 85 percent accounting for human error - forgetting to use one, improper use, poor storage leading to breakage etc.

The contraceptive pill is considered even more effective than the IUD (99.7 percent) but only with 'perfect use', meaning it's taken at the same time every single day.

The 'rod' implant, which is inserted into the arm and can last for up to five years, is considered about as effective as the IUD because again, users don't have to remember to do anything before they have sex. 

How do I get an IUD?


An IUD has to be inserted by a medical professional. You can get it done at a Family Planning clinic or your local GP. From November 1, getting an IUD will be free - Mirena currently costs $340 through Family Planning and about $460 at a private practice, while Jaydess is $275 through Family Planning.  

While you can get an IUD inserted whenever you want (unless you're pregnant), Family Planning recommends going for your appointment during your period or just after because your cervix will be the softest. If you've just given birth, you should wait six weeks before having an IUD inserted. 

How does insertion work?


First your nurse or doctor will ask some questions about your medical history and check your vagina, cervix and uterus to make sure everything's in good working order. They may give you medication to help your cervix relax before inserting a speculum - a device that keeps the vagina open. They'll then use a special tube to push the IUD through the opening of your cervix and into the uterus, where the 'arms' of the device will open. The whole process takes about five minutes. 

Does it hurt?


Insertion can be painful, particularly for women who haven't given birth before. If you're worried about it you can take pain relief medication such as Ibuprofen an hour before the insertion, and it's recommended you eat something beforehand so you don't feel faint. You'll be given time to lie down after the insertion until you feel normal again.

While most people are able to go back to work or school after their appointment, some women do experience moderate to severe cramps as their body gets used to the IUD. These can be treated however you treat regular period cramps. You may want to have a friend or partner pick you up from your appointment just in case. 

copper IUD
The copper IUD can stay in the uterus for longer than a hormonal version. Photo credit: Getty

What about afterwards?


If you are on your period, you should avoid using tampons for the first 48 hours after having an IUD inserted. You should also go in for a check-up six weeks later to make sure it's working how it should.

You can have sex as soon as you want to after getting an IUD, but it can take up to seven days for full pregnancy protection to come into force so use condoms or spermicide for the first week. 

An IUD will have one or two strings dangling from the end that can be felt at the end of the vaginal canal. Family Planning recommends feeling for the strings after every period to check it's still in place - it's rare but not unheard of for an IUD to fall out, in which case it will have to be re-inserted. If you can't feel the strings, make an appointment with your doctor and in the meantime be sure to use non-hormonal birth control such as condoms to prevent pregnancy. 

How does an IUD affect periods?


Many women use hormonal IUDs for period control as well as birth control. While you may bleed more heavily than usual for the first few months after insertion, over time your periods should become lighter and shorter. Some women's periods stop altogether after using an IUD for a while. 

Mirena in particular can be good for people who suffer from endometriosis because the hormones can help control the growth of endometrial tissue. 

Copper IUDs, on the other hand, can make periods heavier and longer for the first few months after insertion. 

How and when does it come out?


Whoever inserts your IUD will let you know when it will need to be removed. Mirena is effective for five years after insertion, Jaydess for three, although copper IUDs can be left in for up to 10 or 12 years. 

You can have your IUD removed at any time before then if you wish to become pregnant, are experiencing distressing side effects or are unhappy with the device and want to use something else. 

The good news is removal is generally much easier than insertion - a medical professional will grasp the strings with forceps and gently pull the IUD out. The 'arms' will fold upward, allowing it to slide out through the cervix.

What can go wrong?


Along with the small risk of the IUD coming out, there's a low chance you could experience a different problem such as not all of the device coming out during removal. There are some very rare cases of an IUD "migrating" through the wall of the uterus which may require surgery to correct.

The first popular IUD, introduced in the 1970s, used a kind of string that made it easier for bacteria to enter the uterus, resulting in a higher chance of pelvic infections. While current models are much safer, the memory of the early devices has left some people with a fear of them that isn't supported by statistics - IUDs (along with implants) have the highest rates of user satisfaction of any form of birth control. 


Contact Newshub with your story tips: