A woman can get pregnant if a man's sperm reaches one of her eggs (ova). Contraception tries to stop this happening by keeping the egg and sperm apart, or by stopping egg production. One method of contraception is the diaphragm.
A diaphragm is a circle of silicone inserted into the vagina before sex to cover the cervix so that sperm can't get into the womb (uterus). You need to use spermicide with it (spermicides kill sperm).
The diaphragm must be left in place for at least 6 hours after sex. After that time, you take out the diaphragm and wash it (they're reusable). Diaphragms come in different sizes. You must be fitted for the correct size by a trained doctor or nurse.
At a glance: contraceptive diaphragm
When used correctly with spermicide, a diaphragm is 92 to 96% effective at preventing pregnancy. This means that between 4 and 8 women out of every 100 who use a diaphragm as contraception will become pregnant within a year.
In real world use about 16 women out of every 100 that use a diaphragm a year become pregnant. This is because people forget to use it or don’t put it in properly (84% effective).
Diaphragms may be more effective in women who haven't had a baby.
There are no serious health risks.
You only have to think about it when you have sex.
You can put a diaphragm in several hours before you have sex.
It can take time to learn how to use it.
Some women develop cystitis (a bladder infection) when they use a diaphragm. Your doctor or nurse can check the size – switching to a smaller size may help.
If you lose or gain more than 3kg (7lbs) in weight, or have a baby, miscarriage or abortion, you may need to be fitted with a new diaphragm.
By using condoms as well as a diaphragm, you'll help to protect yourself against sexually transmitted infections (STIs).
How the contraceptive diaphragm works
A diaphragm is a barrier method of contraception. It fits inside your vagina and prevents sperm from passing through the cervix (the entrance of your womb). Diaphragms are soft, thin domes made of silicone, and come in different shapes and sizes.
To be effective in preventing pregnancy, diaphragms need to be used with spermicide, a chemical that kills sperm.
You only have to use a diaphragm when you have sex, but you must leave it in for at least 6 hours after the last time you had sex. You can leave it in for longer than this, but do not take it out before.
When you first start using a diaphragm, a doctor or nurse will examine you and advise on the correct size to suit you. They'll show you how to put in and take out a diaphragm, and also how to use the spermicide, which must be applied every time you use the diaphragm.
A diaphragm provides less protection against STIs than a condom. Spermicides can irritate the skin in the vagina and make it easier for an STI to be passed from your partner. If you're at a high risk of getting an STI – for example, you or your partner has more than one sexual partner – you may be advised to use another form of contraception.
Inserting a diaphragm
Your doctor or nurse will show you how to put in a diaphragm. Diaphragms come with instructions and are all inserted in a similar way.
- With clean hands, put a small amount of spermicide on each side of the diaphragm. Also putting a little spermicide on the rim may make the diaphragm easier to put in.
- Put your index finger on top of the diaphragm and squeeze it between your thumb and other fingers.
- Slide the diaphragm into your vagina, upwards. This should ensure that the diaphragm covers your cervix.
- Always check that your cervix is covered – it feels like a lump, a bit like the end of your nose.
- If your cervix is not covered, take the diaphragm out by hooking your finger under the rim or loop (if there is one) and pulling downwards.
- Some women squat while they put their diaphragm in; others lie down or stand with one foot up on a chair – use the position that's easiest for you.
- You can insert a diaphragm up to 3 hours before you have sex – after this time, you will need to take it out and put some more spermicide on it.
You may be fitted with a temporary diaphragm by your doctor or nurse. This is for you to practice with at home. It allows you to learn how to use it properly, see how it feels and find out if the method is suitable for you. During this time, you're not protected against pregnancy and need to use additional contraception, such as condoms, when you have sex.
When you go back for a follow-up appointment with your doctor or nurse, wear the diaphragm so they can check that it is the right size and you have put it in properly. When you're happy that you can use a diaphragm properly, they'll give you one to use as contraception.
Removing a diaphragm
A diaphragm can be easily removed by gently hooking your finger under its rim and pulling it downwards and out. You must leave all types of diaphragm in place for at least 6 hours after the last time you had sex.
You can leave them in for longer than this, but do not leave them in for longer than the recommended time of 30 hours.
Looking after your diaphragm
After using, you can wash your diaphragm with warm water and mild unperfumed soap. Rinse it thoroughly, then leave it to dry. You will be given a small container for it, which you should keep in a cool, dry place. Never boil a diaphragm.
Your diaphragm may become discoloured over time, but this does not make it less effective.
Always check your diaphragm or cap for any signs of damage before using it.
You can visit your GP or nurse when you want to replace your diaphragm. Most women can use the same diaphragm for a year before they need to replace it. You may need to get a different size diaphragm if you gain or lose more than 3kg (7lb) in weight, or if you have a baby, miscarriage or abortion.
Who can use a diaphragm?
Most women are able to use a diaphragm. However, they may not be suitable for you if you:
- have an unusually shaped or positioned cervix (entrance to the womb), or if you cannot reach your cervix
- have weakened vaginal muscles (possibly as a result of giving birth) that cannot hold a diaphragm in place
- have had a bladder prolapse repair
- have a sensitivity or an allergy to latex or the chemicals in spermicide
- have ever had toxic shock syndrome (a rare but life-threatening bacterial infection)
- have repeated urinary tract infections (UTI) (infection of the urinary system, such as the urethra, bladder or kidneys)
- currently have a vaginal infection (wait until your infection clears before using a diaphragm or cap)
- are not comfortable touching your vagina
- have a high risk of getting an STI – for example, if you have multiple sexual partners or are unsure of your partners sexual health
Spermicides which contain the chemical nonoxynol-9 do not protect against STIs and may even increase your risk of getting an infection.
A diaphragm may be less effective if:
- it's damaged – for example, it is torn or has holes
- it's not the right size for you
- you use it without spermicide
- you do not use extra spermicide with your diaphragm every time you have more sex
- you remove it too soon (less than 6 hours after the last time you had sex)
If any of these things happen, or you have had sex without contraception, you may need to use emergency contraception.
You can use a diaphragm after having a baby, but you may need a different size. It's recommended that you wait at least 6 weeks after giving birth before using a diaphragm. You can use a diaphragm after a miscarriage or abortion, but you may need a different size.
Advantages and disadvantages of a diaphragm
Advantages of a diaphragm are:
- you only need to use a diaphragm when you want to have sex
- you can put it in at a convenient time (but do not forget to use extra spermicide if you have it in for more than 3 hours) before having sex
- there are no serious associated health risks or side effects
Disadvantages of a diaphragm are:
- it's not as effective as other types of contraception
- it only provides limited protection against STIs
- it can take time to learn how to use it
- putting it in can interrupt sex
- cystitis (bladder infection) can be a problem for some women who use a diaphragm
- spermicide can cause irritation in some women and their sexual partners
Risks of a diaphragm
There are no serious health risks associated with using a contraceptive diaphragm.
Where can you get a diaphragm?
Most types of contraception are free in the UK. Contraception is free to everyone through the NHS. Places where you can get contraception include:
- some GP practices – talk to your GP or practice nurse
- sexual health clinics – they also offer contraceptive and STI testing services
- some young people's services
Contraception services are free and confidential, including for people under the age of 16.
If you're under 16 and want contraception, the doctor, nurse or pharmacists won't tell your parents (or carer). They'll provide you with contraception as long as they believe you fully understand the information you're given and are able to use the contraception safely.
Doctors and nurses have a responsibility to make sure that you are safe and free from harm. They'll encourage you to consider telling your parents (or carer), but they won't make you. The only time that a professional will not be able to keep confidentiality is if they believe you're at risk of serious harm, such as abuse. If this was the case they would usually discuss it with you first.