Other names: barrier method
What is the contraceptive diaphragm?
The contraceptive diaphragm is a dome-shaped flexible disk placed in the vagina before sex. It prevents pregnancy by blocking the entrance of the cervix, preventing sperm from reaching the womb (uterus) to fertilise an egg.
It needs to be put in every time you have sex.
The diaphragm is a type of barrier method
The diaphragm belongs to a group of contraceptives called barrier methods. Barrier contraception methods work by physically stopping the sperm from reaching and fertilising the egg. Some barrier methods (e.g. condoms) also provide protection against some sexually transmitted infections (STIs).
How does the contraceptive diaphragm work?
The contraceptive diaphragm works in two ways to prevent pregnancy:
By covering your cervix, the contraceptive diaphragm acts as a barrier to stop sperm from entering your womb so an egg cannot be fertilised.
The spermicide gel you put on a contraceptive diaphragm kills the sperm if they manage to get under the edge of your contraceptive diaphragm.
How effective is the contraceptive diaphragm
The diaphragm is 88% effective with typical use which means that approximately 12 out of 100 women will get pregnant using this method every year.
With perfect use the diaphragm can be up to 94% effective – this is if it is used perfectly every time, fitted correctly and filled with spermicide.
A diaphragm may be less effective if it is damaged, if it is not the right size for you and if you use it without spermicide.
What is the diaphragm made of?
A contraceptive diaphragm is a circular dome made of latex (rubber) or thin, soft silicone. The diaphragm has a flexible rim which holds it in place. Diaphragms can come in different sizes ranging from 60mm - 95mm (60, 65, 70, 75, 80, 85, 90, 95mm). There are also one-size diaphragms which are 75 mm x 67 mm and can be suitable for a wide range of women. Diaphragms are durable and reusable.
No. The diaphragm is hormone-free and works most effectively when it is used with spermicide.
You're likely to be able to use a diaphragm, but it 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 that cannot hold a diaphragm in place (possibly as a result of giving birth).
Have a sensitivity or an allergy to latex or the chemicals in spermicide.
Have ever had toxic shock syndrome, a very rare but serious bacterial infection.
Have repeated urinary tract infections (UTIs).
Currently have a vaginal infection. You’ll need to wait until your infection clears before using a diaphragm or cap.
Are at higher risk getting an STI – for example, if you have multiple sexual partners.
PP-UN-WHC-GB-0081 September 2023