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Contraceptive diaphragm

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What is a diaphragm?

The contraceptive diaphragm or cap is a barrier method of protection. It’s a circular dome made from soft silicone that is inserted into the vagina before sex. The material means that it is flexible and easy to insert high into your vagina, also you and your partner will not be able to feel the diaphragm when it is in place. It covers your cervix (entrance to the uterus) so that sperm can’t get into your uterus (womb) to fertilise an egg that has been released during ovulation

As a diaphragm doesn't use hormones like many types of contraception it will not affect your menstrual cycle and your periods will not change. Unlike the pill they are also not affected by medicines that you take orally or illnesses that cause you to vomit.

How effective is the diaphragm?

When used correctly with spermicide, a diaphragm or cap is 92-96% effective at preventing pregnancy*. Diaphragms can take a little getting used to, you may want to practise inserting and removing it until you are completely confident in doing so. A diaphragm can be less effective if:

  • It is damaged - it’s important that you take proper care of your diaphragm. Washing your diaphragm with warm water and a mild perfumed soap is all you need to do to keep it in good condition, make sure that you rinse it thoroughly and leave it to dry. When you’re not using it you can keep it in its container to stop it from getting damaged.
  • It’s not the right size for you
  • You don’t use spermicide alongside your diaphragm or you don’t use additional spermicide every time you have sex
  • You remove it less than six hours after you last had sex

How do you use a diaphragm?

The diaphragm is most effective when used with spermicide. The spermicide gel or cream needs to be applied around the edges of the diaphragm so that no sperm can pass around the sides of the diaphragm.

You will only need to have a diaphragm in place when you want to sex, you can put it in at a convenient time for you, however if you have it in for over three hours you will need to use extra spermicide. You don’t need to remove the diaphragm to reapply the spermicide. Once you have had sex you’ll need to leave it in for six hours or more.

Do diaphragms protect against STIs?

A diaphragm does not provide reliable protection against sexually transmitted infections (STIs). As certain STIs can be passed through anal and oral sex, as well as infected genitals coming into contact with your genitals. The diaphragm can only be inserted into your vagina and so during anal sex you will need to use another method of protection, such as condoms.

Who can use a diaphragm?

Most women are able to use a diaphragm; however it may not be a suitable form of contraception for you if you have an unusually shaped or positioned cervix or if you cannot reach your cervix. If you are allergic to latex or the chemicals used in spermicides the diaphragm can cause irritation.

Where can I get a diaphragm?

You can get a diaphragm from your local sexual health clinic, GUM clinic, or your GP surgery. However make sure to check that they offer this service before you visit them, as they may not offer the service or you may need to book an appointment. The first time that you have a diaphragm your nurse or doctor will fit it; you will also be able to discuss the advantages and disadvantages of using one.

You may be given a temporary diaphragm for you to practise with at home, this won’t protect you from pregnancy but it will allow you to perfect inserting and removing it. Your doctor or nurse will then check that the diaphragm is the right size and that it fits properly, once they are confident that you can use it correctly they will give you a diaphragm to use as a contraceptive.

Are there any risks with using a diaphragm?

There are no health risks associated with using a diaphragm, as long as you are using it as instructed. However you should be aware that using a diaphragm while you’re on your period could be linked with toxic shock syndrome (TSS). You may want to consider using another method of contraception when you’re on your period, such as condoms. Some women can develop bladder infections when using the diaphragm, if you are worried or are more prone to cystitis you can talk to your doctor or nurse who can offer advice.