Diaphragm & Cap

These are barrier methods of contraception which fit in the woman’s vagina. They come in different shapes and sizes. Vaginal diaphragms are circular domes made of thin, soft latex (rubber) or silicone with a flexible rim. Cervical caps are smaller devices which are designed to fit neatly over the cervix and are made of latex or silicone.

Diaphragms and caps work in a similar way so the same information applies to both.

They form a barrier at the entrance to the womb (cervix) which stops the sperm getting through to join the egg. To be effective, diaphragms and caps need to be used with a spermicide. Spermicides are chemicals that kill sperm.

If used according to instructions, latex diaphragms and caps are 92-96% effective when used correctly and with spermicide. This means that between four and eight women in 100 will get pregnant in a year.

If they are not used according to instructions, more women will get pregnant. How effective any contraceptive is depends on how old you are, how often you have sex and whether you follow the instructions.

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