The diaphragm is a form of contraception. This page explains how the diaphragm works and tells you how to use it.
What is a diaphragm?
A diaphragm fits inside the vagina and is used each time you have sex. It covers your cervix (entrance to the uterus) and stops sperm from getting through to join an egg.
Diaphragms are domes made of silicone. They are kept in shape by a bendy frame which is covered in silicone. Your pelvic muscles hold the diaphragm in place.
How do you use a diaphragm?
Diaphragms should always be used with spermicide. This is jelly that kills sperm.
Before you have sex, put spermicide onto the diaphragm. Then put it into your vagina so it covers your cervix.
Keep it in place while you have sex and for at least six hours afterwards. Then remove it, wash and dry it and put it away until next time you want to use it.
Where can i get a diaphragm and spermicide?
Diaphragms and spermicide have not been available in Aotearoa New Zealand for a number of years.
A new diaphragm called Caya is now being marketed by a New Zealand distributor. The efficacy data for this one-sized diaphragm is very poor (see below) so we cannot recommend it.
If you already have a diaphragm which is in good order, you can keep using it, but you will have to buy spermicide online and have it sent to New Zealand.
If you have bought or want to buy a diaphragm online, we can help you by making sure it fits well - just let us know when making your appointment that it is about your diaphragm so we can get an experienced nurse to help you.
How safe is it?
The data for the Caya diaphragm with typical use is 10.4 pregnancies per 100 users with 6 months use.
If you use a diaphragm carefully, with spermicide every time you have sex, six out of 100 users will get pregnant each year. With less careful use this could be as high as 16 out of 100 users.
What are the advantages?
- Use only when you have sex
- No hormones
- Few side effects
- Protects your cervix – so can help prevent cancer of the cervix and some sexually transmissible infections (STIs)
- Does not affect your menstrual cycle
What are the disadvantages?
- Must be used every time you have sex
- Some people find that having a diaphragm in their vagina can irritate the bladder, causing an infection
- Some people find the spermicide messy
- Some people are allergic to spermicide
Are all diaphragms the same size?
No. Some diaphragms come in different sizes. The nurse can check whether your diaphragm suits your body.
When your diaphragm fits well, neither you nor your partner should be able to feel it during sex.
Should I have my diaphragm checked?
Yes. You should have your diaphragm checked:
- every year and after any pregnancy or vaginal surgery
- if you gain or lose more than 3 kilograms (1/2 a stone or 7 pounds)
- if you have any problems with it.
Will a diaphragm protect me from STIs?
A diaphragm gives you some protection but it is still recommended that if you are at risk of an STI, your partner should use condoms and lubricant. If there is a chance you may have an STI, have a check-up.
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