Barrier methods of contraception include diaphragms, cervical caps, chemical spermicides, male and female condoms. These methods vary in effectiveness at preventing pregnancy. With both the diaphragm and the cap, the biggest risk factor for unplanned pregnancy is failure to use the devices.

Diaphragms

The diaphragm is a soft latex dome with a flexible rim which is placed inside the vagina to cover the cervix (opening of the uterus). It is held in place by the pelvic muscles and prevents sperm entering the cervix. The diaphragm must be left in place for at least 6 hours after intercourse to allow all sperm to become inactive. Some women choose to use spermicide with the diaphragm to lower the risk of pregnancy, however there is no conclusive evidence either way.

The effectiveness of the diaphragm is affected by many factors including the age and fertility of the woman, how often she has sex and how diligent she is in using her diaphragm. Effectiveness varies between 80-94%.

Two types of diaphragm are available in Australia; the coil spring and all-flex diaphragm. They come in a range of sizes and need to be fitted by a doctor or nurse. Prices range for different types, but average cost is $60-70.

Fitting and using a diaphragm

A clinic visit is necessary for the diaphragm to be correctly fitted. During the visit you will receive instruction on how to insert the diaphragm, how to check the correct position of the diaphragm and how to remove it.

• The diaphragm should be inserted at any convenient time before intercourse. If using a spermicide apply about 1 teaspoon full on the upper surface of the diaphragm. Make sure you or your partner can feel that the cervix is covered by the diaphragm when it is in position.
   

• If you need extra lubrication, use only water-based products such as KY or Wetstuff. Oil-based lubricants, such as vaseline, hand lotions and massage oil, will deterioirate the diaphragm. Some medications for vaginal infections can also perish the diaphragm.
   

• The diaphragm must be left in position for at least 6 hours after intercourse. If you wish, it may be left longer, but should be removed once every 24 hours for cleaning.
   

• Should you have your period while the diaphragm is being worn, the blood will collect behind the diaphragm and eventually overflow. Because of the small chance of infection occurring during your period, it is best to remove the diaphragm as soon as convenient after the minimum 6 hours.

Caring and checking your diaphragm

After taking out your diaphragm wash it with warm water, with mild soap if you wish. Do not use detergent as this will break down the latex in the diaphragm. Rinse and dry it well and store it in the plastic box provided, away from light and heat. To aid drying, the diaphragm may be sprinkled with cornflour. Check it regularly for holes by holding the diaphragm up to the light and stretching it gently between your fingers. Be aware of any tackiness – latex becomes sticky or tacky when it is beginning to perish. If it does develop a tear or hole or becomes smelly, do not use it, replace it promptly.

If you wish to wear your diaphragm almost continuously (only removing it each day for cleaning), it is a good idea to have two diaphragms so that they can be alternated. This will reduce the chance of the diaphragm becoming smelly.

If your diaphragm is uncomfortable

If your diaphragm has been properly fitted and is in the right position in the vagina you should be unaware of it. However if your diaphragm is uncomfortable (for you or your partner), you feel sore after using it, or you have urinary discomfort, see your doctor or nurse. You may need a different size or type, or need to discuss an alternative method of contraception.

When to get a new diaphragm

Usually a diaphragm will last for about 2 years depending on how often it is used and how you care for it. You should have your diaphragm checked for size if you have a pregnancy, pelvic surgery or if your weight changes by more than 5kg. You may like to bring your diaphragm along to have the size checked when you go for your routine Pap smear.

Advantages

• A diaphragm does not interfere with your hormone levels.
• It can be inserted at any convenient time prior to intercourse and need not interfere with sexual spontaneity.
• Some women use a diaphragm when they have sex during their period to stop blood flowing out.

Disadvantages

• Use of the diaphragm requires learning correct insertion techniques.
• A few people are allergic to latex or spermicide if used.
• The risk of pregnancy is higher than for some other methods of contraception.
• Not all women feel comfortable touching their genitals and some have difficulty feeling their cervix.

Caps

Like the diaphragm, the cap is made of soft latex and reduces the risk of pregnancy providing a barrier to prevent sperm entering the cervix. Caps are smaller than diaphragms, fit closely over the cervix and are held in place by suction. Different types and sizes are available. You will need to be examined to decide which cap is most suitable. The instructions on fitting and using caps vary between types.

Advantages

Caps:

• do not interfere with your hormone levels
• may be suitable for women with poor muscle tone or degrees of prolapse
• are unlikely to cause urinary discomfort
• size required is not affected by changes in bodyweight

Disadvantages

Caps:

• can be dislodged from the cervix during intercourse without the woman being aware of it
• may be more difficult to fit

Spermicides

They can be used alone although but are often used with diaphragms and caps. There are many types of spermicide available. In Australia they include foam, gels and creams. When used on its own foam is said to be more effective than gel when used alone. Spermicides are not very effective at preventing pregnancy. It is recommended, therefore, that spermicide be used with another barrier method of contraception. There is some evidence that regular use of spermicides can cause damage to the vaginal skin thereby increasing the possible risk of contracting STIs and HIV.

Recommended spermicides can be purchased at FPWA or from pharmacies for around $15.

What to do if a method is not correctly used

Emergency contraception (morning after pill) is available if the diaphragm or cap is displaced or not used. Emergency contraception needs to be taken as soon as possible after unprotected sex, though it provides some effectiveness for up to 3 days.

Unprotected sex also puts you at risk of HIV and other STIs. Screening for these infections can be provided at FPWA and is recommended if you have any concerns.

If you have had unprotected sex with someone who may be HIV positive, drug treatment can reduce your risk of acquiring HIV. If you are in this situation contact your doctor or FPWA.

Practising safe sex reduces the risk of contracting HIV and other sexually transmissible infections (STIs).