The diaphragm and cervical cap are small bowl-shaped domes made out of silicone or latex which fit inside the vagina and cover the cervix, making a barrier between the vagina and the cervix.
Diaphragms and caps are always used with spermicide, a chemical gel or foam that kills sperm.
How do diaphragms and cervical caps work?
They create a barrier between the vagina and the cervix, preventing sperm from being able to enter the canal to the womb and travel to meet an egg.
The spermicide used with the diaphragm also kills the sperm.
The diaphragm and cap, with spermicide, can be put in up to three hours before sex. It must not be removed sooner than six hours after sex.
How effective is this method?
When fitted correctly and used with spermicide the diaphragm is 92-96% effective in preventing pregnancy.
Advantages of diaphragms and cervical caps:
- they can be put in before sex and so don't interrupt things
- they have no health risks associated with them
- they're a non-hormonal method of contraception
- some research suggests that using the diaphragm may provide some protection against cervical cancer, and some sexually transmitted infections because the diaphragm covers and protects key body parts at risk of infection
- diaphragms are available in both latex and non-latex so people with a known latex allergy can still use them
Disadvantages of diaphragms and cervical caps:
- it can take a while for you to get the knack of fitting them correctly
- you may find the spermicide messy
- some people find spermicide irritates their skin, or that using the diaphragm causes cystitis
- they are not as effective in preventing pregnancy as most other types of contraception
Things to bear in mind:
If you gain or lose weight your diaphragm may not fit properly and will be less effective. If your weight changes, it is important to see a doctor or nurse to get a new diaphragm.
Most importantly, the diaphragm does not provide any protection against HIV - although it may protect against some other sexually transmitted infections.
Where can I get it from and how much does it cost?
The diaphragm is available free on the NHS. You can only get it on prescription. This can be from your GP, a practice nurse, a sexual health clinic or young person's clinic.