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 cap.
The contraceptive cap is a circular dome made of thin, soft silicone (they used to be made of latex, but if you get a cap on the NHS today it will be made of silicone). It's inserted into the vagina before sex, and covers the cervix so that sperm cannot get into the womb. You need to use spermicide with it (spermicide kills sperm).
The cap must be left in place for six hours after sex. After that time, you take out the cap and wash it. Caps are reusable. They come in different sizes, and you must be fitted for the correct size by a trained doctor or nurse.
At a glance: facts about the cap
- When used correctly with spermicide, the cap is 92-96% effective at preventing pregnancy. This means that between four and eight women out of every 100 who use a cap as contraception will become pregnant in a year.
- There are no serious health risks.
- You only have to think about it when you have sex.
- You can put a cap in several hours before you have sex.
- It can take time to learn how to use a cap.
- 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 cap.
- By using condoms as well as a cap, you will help to protect yourself against sexually transmitted infections (STIs).
How the cap works
A cap, like a diaphragm, is a barrier method of contraception. It fits inside your vagina and prevents sperm from passing through the entrance of your womb (the cervix). Caps are soft, thin domes made of silicone, and come in different shapes and sizes.
You can get contraception at:
- most GP surgeries
- community contraception clinics
- some GUM clinics
- sexual health clinics
- some young people's services
To be effective in preventing pregnancy, a cap needs to be used in combination with spermicide, which is a chemical that kills sperm.
You only have to use a cap when you have sex, but you must leave it in for at least six 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 cap, a doctor or nurse will examine you and advise on the correct size or shape. They will show you how to put in and take out the cap, and also how to use the spermicide, which must be applied every time you use a cap.
A cap provides only limited protection against STIs. 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 contraceptive cap
Your doctor or nurse will show you how to put in a cap. Caps come with instructions and are all inserted in a similar way:
- With clean hands, fill one-third of the cap with spermicide, but do not put any spermicide around the rim, as this will stop the cap staying in place.
- The silicone cap has a groove between the dome and the rim - some spermicide should also be placed there.
- Squeeze the sides of the cap together and hold it between your thumb and first two fingers.
- Slide the cap into your vagina, upwards.
- The cap must fit neatly over your cervix - it stays in place by suction.
- Depending on the type of cap, you may need to add extra spermicide after it has been put in.
- Some women squat while they put their cap in, while others lie down or stand with one foot up on a chair - use the position that's easiest for you.
- You can insert a cap up to three 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 cap by your doctor or nurse. This is for you to practise with at home. It gives you the chance 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 are 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 cap so they can check that it is the right size and you have put it in properly. When they are happy that you can use a cap properly, they will give you one to use as contraception.
Removing a cap
A cap can be easily removed by gently hooking your finger under its rim, loop or strap and pulling it downwards and out. You must leave all types of cap in place for at least six 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 maximum time of 48 hours (including the minimum six). A latex cap should not be left in for more than 30 hours.
Looking after your cap
After use, you can wash your cap with warm water and mild, unperfumed soap. Rinse it thoroughly, then leave to dry. You will be given a small container for it, which you should keep in a cool, dry place.
- Never boil a cap.
- Do not use disinfectant, detergent, oil-based products or talcum powder to keep it clean, as these products can damage it.
- Your cap may become discoloured over time, but this does not make it less effective.
- Always check your cap for any signs of damage before using it.
You can visit your GP or nurse when you want to replace your cap. Most women can use the same cap for a year before they need to replace it. You may need to get a different sized cap if you gain or lose more than 3kg (7lb) in weight, or if you have a baby, miscarriage or abortion.
Who can use the cap
Most women are able to use contraceptive caps. 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 cap in place
- have a sensitivity or an allergy to the chemicals in spermicide (or latex, if you have a latex cap)
- have ever had toxic shock syndrome (a rare, but life-threatening bacterial infection)
- have repeated urinary tract infections (an 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
Research shows that spermicides which contain the chemical nonoxynol-9 do not protect against STIs and may even increase your risk of getting an STI.
A cap may be less effective if:
- it is damaged - for example, it is torn or has holes
- it is not the right size for you
- you use it without spermicide
- you do not use extra spermicide with your cap every time you have more sex
- you remove it too soon (less than six hours after the last time you had sex)
- you use oil-based products, such as baby lotion, bath oils, moisturiser or some vaginal medicines (for example, pessaries) with a latex cap - these can damage the latex
If any of these things happen, or you have had sex without contraception, you may need emergency contraception.
You can use a cap after having a baby, but you may need a different size. It is recommended that you wait at least six weeks after giving birth before using a contraceptive cap. You can use a cap after a miscarriage or abortion, but you may need a different size.
Advantages and disadvantages of the cap
A cap has the following advantages:
- you only need to use it when you want to have sex
- you can put it in at a convenient time before having sex (do not forget to use extra spermicide if you have it in for more than three hours)
- there are no serious associated health risks or side effects
A cap has the following disadvantages:
- it is not as effective as other types of contraception
- it only provides limited protection against STIs
- it can take time to learn how to use a cap
- putting a cap in can interrupt sex
- cystitis (bladder infection) can be a problem for some women who use a cap
- latex and spermicide can cause irritation in some women and their sexual partners
There are no serious health risks associated with using a contraceptive cap.
Where you can get it
Most types of contraception are free in the UK. Contraception is free to all women and men through the NHS. Places where you can get contraception include:
- most GP surgeries - talk to your GP or practice nurse
- community contraception clinics
- some genitourinary medicine (GUM) clinics
- sexual health clinics - they also offer contraceptive and STI testing services
- some young people's services (call the Sexual Health Line on 0300 123 7123 for more information)
Find your nearest sexual health clinic by searching by postcode or town. 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) as long as they believe you fully understand the information you're given, and your decisions. Doctors and nurses work under strict guidelines when dealing with people under 16. They'll encourage you to consider telling your parents, but they won't make you. The only time that a professional might want to tell someone else is if they believe you're at risk of harm, such as abuse. The risk would need to be serious, and they would usually discuss this with you first.
Article provided by NHS Choices