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 repeatedly, and it can last up to 2 years if you look after it.

What types of diaphragms are available?

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 effective is the diaphragm as a contraceptive?

Diaphragms work fairly well if they are put in place and used correctly, but are not as effective as the pill, a contraceptive implant or an IUD. If 100 women use a diaphragm for a year, around 18 will likely get pregnant.

When used with another barrier method, such as the condom, the effectiveness of the diaphragm is increased

What could go wrong?

The diaphragm cannot protect you from getting pregnant if it is not put in the correct place, or moves out of place during sex.

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).

What are the advantages and disadvantages of the diaphragm?

Some of the main advantages are that it:

• does not 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 a 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.

More information

See Family Planning NSW, which has a full range of fact sheets on contraception, including diaphragms and how to use them, and Jean Hailes for Women's Health.