This article on the Intra Uterine Device / IUD contraceptive explains how it works, who IUDs are suitable for, and the advantages & disadvantages of intra uterine devices.

What is an Intra Uterine Device

IUD stands for Intra Uterine (within the womb) device – which is a small piece of plastic with copper wire wrapped around it which is placed in the womb, with thin nylon threads that pass through the cervix, into the vagina.

What is the Mirina – or hormonal IUD?

This has progesterone hormone, rather than copper wire. It is equally effective in preventing pregnancy and is more suitable for women who have heavy periods, so would not benefit from the standard IUD.

Where and when can you get an IUD fitted?

Your IUD should be fitted by a specially trained nurse or doctor. The service is available at Family Planning Centres (FPC), doctor’s surgeries or hospital clinics.

Prior to having an IUD fitted you will be asked to have a health check to rule out infection and the pros and cons will be explained to you, to be sure this is suitable for you.

It will be fitted during or just after your menstrual period, or 6 weeks after having a baby, or as emergency contraception if appropriate. The procedure involves stretching your cervix – the opening to your womb – and may hurt for a minute or two. You may wish to take pain killers and have someone with you for support.

How does an Intra Uterine Device work?

Each month, in the middle of her menstrual cycle, a woman releases an egg from one of her two ovaries. It travels down the fallopian tubes towards the uterus or womb, where it may be fertilized by sperm from the man. It then implants in the womb to form a pregnancy.

The IUD prevents the sperm from travelling to the egg. It also prevents the egg from implanting in the wall of the womb.

The IUD is placed in the womb by a specially trained doctor or nurse. The threads attached to the IUD hang in the vagina – this means that the woman can check her IUD is safely in place; it also means it can be easily removed by a doctor or nurse.

How much do IUDs cost?

The FPC require 3 appointments to insert an IUD

  • Firstly to do an infection screen
  • Secondly to fit the IUD
  • Thirdly a follow up check

Each appointment costs $5 if you have a Community Service Card, or $40-50 if you do not. This cost includes a standard IUD.

Mirina IUDs cost approximately $300-350, unless it is subsidised by PHARMAC, because you have heavy menstrual bleeding.

You will usually have to pay for appointments with your doctor or FPC to have it inserted also.

What is the success rate of IUDs?

IUDs are 99% successful at preventing pregnancy. For every 100 women using an IUD for 1 year, one will get pregnant.

IUDs do NOT prevent sexually transmitted infections or STIs. It is necessary to use a condom also to prevent infection.

Also this is not a suitable form of contraception if either partner is having sex with someone else and therefore at increased risk of infection.

What are the risks with IUD?

  • The main risk is getting a pelvic infection when the IUD is inserted, or as a result of a STI.
  • Pelvic infection can cause infertility.
  • There is a 1 in 2000 risk of ectopic pregnancy (pregnancy outside the womb) if the IUD fails.
  • Copper can cause a rare allergic reaction
  • The IUD can cause a perforation to the wall of the womb during insertion

What are the pros?

  • This is a reliable method of contraception.
  • It can last up to 5 years, although annual checks are recommended
  • It does not affect your natural fertility once it is removed.
  • It is suitable during breast feeding
  • Can be used as emergency contraception after unplanned intercourse
  • Your partner probably will not feel the nylon threads during intercourse and it does interrupt intercourse.

What are the cons, side effects or complications?

  • IUD can cause heavier periods and cramping
  • Some women feel faint when the IUD is inserted or removed and this can be uncomfortable
  • It is not suitable for women who have had an infection of the womb or fallopian tubes, women who have a STI, or women who may be pregnant.
  • Also, if you have more than one sexual partner, have heavy periods, have never had a child or have had an ectopic pregnancy – this may not be suitable for you. Speak to your doctor.
  • It is possible that the IUD could fall out itself – hence why you will be taught to feel regularly for the threads after each menstrual period, to be sure it is still in place. Likewise if you have an unusual discharge or bleeding go to your doctor or FPC for a check up.
  • If you suspect you are pregnant see your doctor or FPC. The IUD will need to be removed if you are pregnant to prevent increased risk of miscarriage or infection.

Useful websites & articles

For information on Condoms, click here

To find your local Family Planning Clinic in NZ visit- www.familyplanning.org.nz

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Paula Skelton is a qualified NZ nurse and midwife, a midwifery & childbirth educator and the mum of three lovely girls.

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ashley j

Hi, i currently have an i.u.d. in that has been in as of October 2012, the last four days have been very unusual, cramps, spotting, tender breasts, vomiting, im just wanting to know as iv searched high and low on statistics about conception with an i.u.d. in and have only found that 1 in 100 women conceive with an i.u.d. in for one year, as mine is almost been in for 3 what is the likeliness of me falling pregnant please help 🙂



I am looking into getting a non hormonal IUD and am 21. In regards to having one sexual partner, how painful is it to be removed, if the relationship ends? Also is there any truth that it is not as recommend for younger women who have not had children?



Hi there – can you tell when the ‘little Mirena’ (Skyla) will become available in New Zealand?


How do u apply to get the cost of your mirena subsidised

Rochelle Gribble

Hi Betty,

You need to talk to your doctor or Family Planning Clinic about this.




Hi – I would prefer the non hormonal IUD fitted. Do I need to let the FPC know this when I book my appointment? And have you an idea on cost. I work full time, no community card.

Rochelle Gribble

Hi Hazel,

You’d be best to chat with your local FPC clinic about this when you call – they can give you the specific details.

Good luck!


Rajesh Rao

I am presently researching the topic and have noticed that you have spelt the Mirena as Merina. And IUD is not inter uterine but intra uterine.Otherwise, it is an educative article.

Rochelle Gribble

Hi Rajesh,

Thanks for pointing that out! I’ve fixed that up 🙂



Hi Rochelle
I had a copper IUD fitted a week ago, and felt for the threads this morning but they feel a lot longer than I would have expected, what length should you usually feel?


hi I have had the merina 4 2 yrs now al been fine but 4 the last 3 days have had alot of pain is it possible 4 it 2 fall out without noting it.

Rochelle Gribble

Hi Marina,

If you’re in pain, it’s best to get your doctor to check it out for you.




If you’re under 21, is the IUD cheaper?

Rochelle Gribble

Hi AAmanda,

You’d be best to contact your local Family Planning Clinic to find out the details – http://www.familyplanning.org.nz




Hi, if i have the IUD removed how long does it take normally to get pregnant?

Rochelle Gribble

Hi Paula,

It’s impossible to say how long it will take for you as everyone is different but it’s common to take 4-6 months. Approximately 85-90% of people will conceive within a year. You’re best to talk to your GP or Family Planning Doctor about this if you are considering getting pregnant.

Kind regards,



Hi, in the cons, side affects, complications it says that it may not be suitable if you have not had children – why is that??

Rochelle Gribble

Hi Sunnydays,

There’s an interesting comment about it here: http://goaskalice.columbia.edu/mirena-it-safe-woman-without-children but the best thing to do it talk to your GP or an organisation like Family Planning- http://www.familyplanning.org.nz/




I was told that the IUD is now funded by the government if you are on the benefit?

Rochelle Gribble

Hi Myfamilyof3,

There was some talk of this in the media but I’m not sure that it has actually happened. However, you’d be best to talk to your gp or local Family Planning http://www.kiwifamilies.co.nz/articles/family-planning-new-zealand/ about it. 



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