The diaphragm is a type of contraception that women can use to avoid getting pregnant. It sits inside the vagina and prevents sperm reaching the womb.
What is a diaphragm?
The diaphragm is a piece of soft silicone in the shape of a dome. You put it into your vagina and move it up to cover the cervix, which is the entrance to the uterus (womb).
Once you insert a diaphragm, it is held in place by your pelvic muscles. You don't need a doctor to insert it, although it is a good idea to see a health professional to learn how to insert it and whether the diaphragm fits your cervix.
How does the diaphragm work?
During sex, the diaphragm stops sperm from entering the uterus. It forms a physical barrier between the man's sperm and the woman's egg, like a condom. So it is sometimes called a barrier method of contraception.
The diaphragm needs to stay in place for at least 6 hours after sex. After 6 — but no longer than 24 hours after sex — it needs to be taken out and cleaned.
You can use the same diaphragm more than once, and it can last up to 2 years if you look after it.
Types of diaphragm
Caya is the only type of diaphragm available in Australia. It comes in only one size, and fits about 8 women out of 10. A health professional will be able to help you select another form of contraception if the diaphragm is not suitable for you.
How well does the diaphragm work?
Diaphragms work fairly well if they are put in place and used correctly, but not as well as the pill, a contraceptive implant or an IUD. If 100 women use a diaphragm for a year, around 12 will likely get pregnant.
Family Planning NSW has a full range of fact sheets on contraception, including information on diaphragms and how to use them.
When used with another barrier method, such as the condom, their effectiveness is increased.
What could go wrong?
The diaphragm can’t protect you from getting pregnant if it is not put in place properly, or moves out of place during sex. A health professional can show you how to fit a diaphragm before you use it for the first time.
If you take it out before 6 hours have passed after sex you risk becoming pregnant.
Your diaphragm could also break, tear, or develop tiny holes — which happens as it gets older — and this too could lead to an unintended pregnancy. You should examine your diaphragm for damage prior to using.
If you had a problem when using a diaphragm and are worried you could have become pregnant, you might want to consider taking emergency contraception, available from your doctor, chemist, health centre or family planning clinic. This should be taken as soon as possible (within 5 days, but sooner is better).
Advantages and disadvantages of the diaphragm
Some of the main advantages are that it:
- doesn't contain any hormones (and can be used if you are breastfeeding)
- only needs to be used when having sex
- can protect against pregnancy straight away
- can be used more than once
The main disadvantages are that:
- it is less effective than many other methods of contraception
- some women find a diaphragm difficult to insert and risk placing it incorrectly
- it needs to be inserted into the vagina before sex
- inserting and removing it may be uncomfortable, and may increase the risk of urinary tract infection
Diaphragms and STIs
A diaphragm won’t protect you against sexually transmitted infections (STIs) – only condoms can do that, and even condoms won’t protect you against every STI.
Find out more about sexual health here.
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Last reviewed: February 2019