What is a diaphragm?

A diaphragm is a type of contraception (birth control) that can be used to avoid getting pregnant. It is a piece of soft silicone in the shape of a dome.

When using a diaphragm, you put it into your vagina before having sex. It should be positioned to cover your cervix (lower part of your womb). This prevents sperm from entering your uterus (womb).

Once you place a diaphragm, it’s held in position by your pelvic muscles. You don’t need a doctor to insert it. But it’s a good idea to see a doctor or nurse to learn how to put it in, and to check the diaphragm fits properly.

How does a diaphragm work?

During sex, a diaphragm stops sperm from entering the uterus. It forms a physical barrier between the sperm and egg. So, it is sometimes called a ‘barrier method’ of contraception or birth control.

Your diaphragm needs to stay in place for at least 6 hours after sex.

Do not leave your diaphragm in for longer than 24 hours. It needs to be taken out and washed every 24 hours.

You can use the same diaphragm repeatedly. 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. Make sure you follow the instructions on how to use it.

You should also use the lactic acid gel (brand name Caya gel) that comes with the diaphragm. The gel should be placed on the dome of the diaphragm. Put 4mL (about a teaspoon) of gel on the side that will face the cervix.

Caya comes in only one size, and fits about 8 out of 10 users. Your doctor will be able to help you choose 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 they are not as effective as a contraceptive implant or an intrauterine device (IUD).

Typically, just under 1 in 5 people using a diaphragm will get pregnant.

When used with another barrier method, such as a condom, the diaphragm is more effective at preventing pregnancy.

What can make a diaphragm less effective at preventing pregnancy?

A diaphragm cannot protect you from getting pregnant if it:

• is not put in the correct place
• moves out of place during sex
• is damaged
• is not used properly

If you take your diaphragm out before 6 hours have passed after sex, you risk becoming pregnant.

Your diaphragm can break, tear, or develop tiny holes — which happens as it gets older. You should check your diaphragm for damage before each use.

If you’ve had a problem when using a diaphragm and are worried you could have become pregnant, you might want to consider taking emergency contraception.

What are the advantages and disadvantages of diaphragms?

Some of the main advantages with diaphragms are that they:

• do not contain any hormones (and can be used if you are breastfeeding)
• only need to be used around the time of having sex
• can be used more than once
• are cost-effective

The main disadvantages with diaphragms are that:

• they are less effective than many other methods of contraception
• some women find diaphragms difficult to put in, and risk placing it incorrectly
• they need to be put into the vagina before sex
• putting them in and taking them out may be uncomfortable
• they are not recommended for use while you have your period
• they won’t protect you against sexually transmitted infections (STIs)

You should not use diaphragms if you have ever had toxic shock syndrome.

Resources and support

Family Planning Australia has a full range of fact sheets on contraception.

You can find out more about sexual health here.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with 24 hours a day, 7 days a week.