Diaphragms and caps are barrier methods of contraception. They fit inside your vagina and prevent sperm from passing into the entrance of your womb (the cervix).

Diaphragms are soft domes made of latex or silicone. Caps are smaller and are also made of latex or silicone.

To be effective, diaphragms and caps need to be used in combination with spermicide, a chemical that kills sperm.

How effective are diaphragms and caps?

If used correctly and in combination with spermicide, diaphragms and caps are estimated to be 92-96% effective in preventing pregnancy.

There are other more effective contraceptives available, such as the oral contraceptive pill. Some women prefer to use diaphragms or caps because they do not like taking the pill. Others cannot take the pill for health reasons.

Diaphragms and caps only provide limited protection against sexually transmitted infections (STIs) such as HIV.