Diaphragms and caps
NHS Direct Online Health Encyclopaedia
Diaphragms and caps are barrier methods of contraception. Diaphragms are made from a type of soft rubber that fits inside the vagina, covering the cervix, the entrance to the womb . Caps tend to be smaller and more rigid than diaphragms. To be effective, diaphragms and caps need to be used with a spermicide. Spermicide contains a chemical that damages and destroys the sperm in semen.
A doctor or nurse will need to fit the diaphragm or cap initially to ensure that it is the right shape and size for you, and then you will be taught how to insert it properly. Some GPs and practice nurses will fit IUDs, but not all. Alternatively you can go to a family planning clinic or sexual health clinic.You can ask to see a female GP in your practice for contraception only.
A diaphragm or cap should be fitted before sex, and kept in for at least 6 hours afterwards. If you have sex more than 3 hours after insertion of the diaphragm, more spermicide needs to be inserted into the vagina.
There are three types of diaphragm available to women in the UK: flat, coil and arcing spring. There are also three types of cap: vault, cervical and vimule, although new varieties such as a silicone cap are becoming available. Diaphragms and caps are between 92% and 96% effective in preventing pregnancy, if used in conjunction with a spermicide. Spermicide is available in a variety of forms including pessaries (tablets placed in the vagina), creams, or jelly.
How does it work?
The diaphragm or cap fit inside the womans vagina and acts as a barrier, preventing sperm traveling to the cervix and the womb. It should be used with a spermicide, which contains a chemical that kills sperm.
Diaphragms and caps do not interfere with hormone levels.
Diaphragms and caps only need to be used when you want to have sex.
You are in control of your contraception.
Neither you nor your partner should be aware that the diaphragm or cap, when having sex .
Diaphragms and caps may offer some protection against some sexually transmitted infections (STIs) and against cancer of the cervix.
Some couples find a diaphragm or cap to be an intrusive method of contraception, because fitting them can interrupt sex if you havent inserted it beforehand.
As they are used in conjunction with spermicides, some people find them a messy contraception method.
It takes time and practice to use one easily and correctly.
It is important that the right size and shape of diaphragm or cap is used. An ill-fitting one may move or slip, increasing the risk of pregnancy. Diaphragms and caps must be checked by a doctor or nurse every six months to nine months.
If you lose or gain a significant amount of weight 3kg (7 pounds) you should see a doctor to make sure the diaphragm or cap still fits properly. You may also need a difference size or shape after giving birth or having a miscarriage or abortion.
Some research suggests that recurring bouts of cystitis and other urinary system infections may be associated with the use of diaphragms and caps (although changing to a smaller size cap or diaphragm may help).
They only offer limited protection against HIV and other sexually transmitted infections (STIs)
Who can use it?
Most women are able to use diaphragms and caps.
However, this method of contraception may be unsuitable for women who have an unusual shaped cervix, a cervix which cant be reached or have weak vaginal muscles, which cannot hold it in place.
A diaphragm or cap can be used while a woman is menstruating.
A few people are allergic to latex or spermicide, so they are unsuitable if either sexual partner has an allergy or sensitivity to rubber or the chemicals found in spermicides. However, more sensitive caps made from silicone are now available for those with rubber allergies.
Women who have had Toxic Shock Syndrome or recurring urinary or vaginal infections will also need to consult with a doctor before choosing to use this method of contraception.
Queen's Printer and Controller of HMSO, 2005
Crown copyright material is reproduced with the permission of the controller of HMSO and the Queens Printer for Scotland.