The Contraceptive Diaphragm - What is it and How Does it Work?

Diaphragms are dome-shaped devices made from rubber or silicone. They are the size of the palm of your hand and designed to form a physical barrier that stops sperm from getting past.

Dr Simran Deo Medical Editor

Medically reviewed by

Dr Simran Deo

Last reviewed: 13 Dec 2019

What is a Diaphragm?

Diaphragms are dome shaped devices made from rubber or silicone. They are designed to literally form a barrier that stops sperm from getting past, and they are about as wide as the palm of your hand. 

Who Can Use a Diaphragm?

Most women are able to use a diaphragm without any problems. They can be a good option for you if you don’t like using condoms, can’t take the pill or use hormonal contraception, and don’t want to use an Intrauterine Device (IUD/Contraceptive coil)

How Does a Diaphragm Work?

A diaphragm works by creating a barrier to sperm, which stops them passing into your uterus and fertilising an egg. It needs to be inserted before you have sex, and used in combination with spermicide. 

How Do You Use a Diaphragm?

A diaphragm has to be inserted high into your vagina, so that it covers your cervix. They are flexible enough to be folded up and easily inserted. The top end of the dome fits behind your cervix, and the bottom should be positioned behind your pubic bone. Neither you or your partner should be able to feel it while you’re having sex.Before you insert it, a special gel or cream has to be applied to it which stops any sperm from getting around the edges of the diaphragm. Without this spermicide, a diaphragm is much less effective in preventing pregnancy.After you’ve had sex you must leave your diaphragm in place for at least six hours. You can then remove it easily by just hooking the tip of your finger around it.  If you decide to have a diaphragm fitted, you’ll need to make an appointment with your doctor or sexual health clinic, who will  make sure you use the right shape and size diaphragm. A doctor or nurse will examine you before fitting the diaphragm, and will also give you advice about how to insert it and remove it.

How Effective is a Diaphragm?

As long as it’s used correctly and with spermicide, a diaphragm is 92–96% effective at preventing pregnancy. To put that into context, out of every 100 women that use a diaphragm as their type of contraception between four and eight will become pregnant within a year.

Are Diaphragms Reusable?

Yes, they are designed to be reused. However, if you notice any damage to it, get it replaced straight away as it won’t be effective. If you take care of your diaphragm it should last you for at least a year before you need to replace it. Wash it with warm water and unperfumed soap after taking it out. Rinse it thoroughly and leave it to dry, then put it back in the special container used to store it. Keep it in a cold, dry place when you’re not using it.Don’t use products like detergent, disinfectant or oil based cleaning products to clean your diaphragm as this might damage it and make it less effective.

Are They Uncomfortable?

A diaphragm is designed so that you can’t feel it once it’s been inserted. If you feel any discomfort, go back to your doctor as you might need a different shape or size.

What Are the Advantages and Disadvantages of a Diaphragm?

On the plus side:

  • there are no serious health risks associated with using a diaphragm
  • you only have to think about contraception when you have sex
  • You can insert it in advance, hours before you actually have sex
  • If you also use condoms you'll protect yourself against sexually transmitted infections (STIs).


  • it can take a while to get the hang of using a diaphragm
  • you could be more prone to cystitis if you use one (although changing to a smaller diaphragm may help.)
  • some women can develop an allergy to the material the diaphragm is made from, or the spermicides used with it.
  • if you lose or gain more than 3kg (7lbs) you may have to be fitted for a new diaphragm
  • if you give birth, have an abortion or a miscarriage, you might also need to be fitted with a new diaphragm

Can Using a Diaphragm Cause Toxic Shock Syndrome?

It’s possible to develop Toxic Shock Syndrome (TSS) while using a diaphragm. If you develop a high fever and start to vomit, remove the diaphragm and get medical help immediately. In cases where TSS has been linked to diaphragms, the diaphragm had been left in the vagina for a long time  - over 30 hours. It’s important to remember to remove your diaphragm ideally within six to eight hours after having sex but no longer than 30 hours.

Will a Diaphragm Stop My Period?

No, a diaphragm will not stop you from having periods. Some women use them if they want to have sex during their period as they trap the menstrual blood and there’s no sign that they are having their period while having sex.


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