Effectiveness depends on the user: Risk of pregnancy is greatest when the diaphragm with spermicide is not used with every act of sex.

• As commonly used, about 17 pregnancies per 100 women using the diaphragm with spermicide over the first year. This means that 83 of every 100 women using the diaphragm will not become pregnant.
• When used correctly with every act of sex, about 16 pregnancies per 100 women using the diaphragm with spermicide over the first year.

Return of fertility after use of the diaphragm is stopped: No delay

Protection against STIs: May provide some protection against certain STIs but should not be relied on for STI prevention

Side Effects

Some users report the following:

• Irritation in or around the vagina or penis

Other possible physical changes:

• Vaginal lesions

Known Health Benefits

Help protect against:

• Risks of pregnancy

May help protect against:

• Certain STIs (chlamydia, gonorrhea, pelvic inflammatory disease, trichomoniasis)
• Cervical precancer and cancer

Known Health Risks

Common to uncommon:

• Urinary tract infection

Uncommon:

• Bacterial vaginosis
• Candidiasis

Rare:

• Frequent use of nonoxynol-9 may increase risk of HIV infection

Extremely rare:

• Toxic shock syndrome

Safe and Suitable for Nearly All Women

Nearly all women can use the diaphragm safely and effectively

Diaphragms:

• Do not affect the feeling of sex. A few men report feeling the diaphragm during sex, but most do not.
• Cannot pass through the cervix. They cannot go into the uterus or otherwise get lost in the woman’s body.
• Do not cause cervical cancer.

Problems Reported as Side Effects or Problems With Use

Difficulty inserting or removing diaphragm

• Difficulty inserting or removing diaphragm
• Discomfort or pain with diaphragm use
• Irritation in or around the vagina or penis (she or her partner has itching, rash, or irritation that lasts for a day or more)
• Urinary tract infection (burning or pain with urination, frequent urination in small amounts, blood in the urine, back pain)
• Bacterial vaginosis (abnormal white or gray vaginal discharge with unpleasant odor; may also have burning during urination and/or itching around the vagina)
• Candidiasis (abnormal white vaginal discharge that can be watery or thick and chunky; may also have burning during urination and/or redness and itching around the vagina)
• Suspected pregnancy

New Problems That May Require Switching Methods

May or may not be due to the method.

• Recurring urinary tract infections or vaginal infections (such as bacterial vaginosis or candidiasis)
• Latex allergy (redness, itching, rash, and/or swelling of genitals, groin, or thighs [mild reaction]; or hives or rash over much of the body, dizziness, difficulty breathing, loss of consciousness [severe reaction])
• Toxic shock syndrome (sudden high fever, body rash, vomiting, diarrhea, dizziness, sore throat, and muscle aches).

• Is the diaphragm uncomfortable for the woman?

No, not if it is fitted and inserted correctly. The woman and her partner usually cannot feel the diaphragm during sex. The provider selects the properly sized diaphragm for each woman so that it fits her and does not hurt. If it is uncomfortable, she should come back to have the fit checked and to make sure that she is inserting and removing the diaphragm properly.

• If a woman uses the diaphragm without spermicides, will it still prevent pregnancy?

There is not enough evidence to be certain. A few studies find that diaphragm users have higher pregnancy rates when they do not use a spermicide with the diaphragm. Thus, using a diaphragm without spermicide is not recommended.

• Could a woman leave a diaphragm in all day?

Yes, although doing so is usually not recommended. A woman could leave a diaphragm in all day if she cannot put it in shortly before having sex. She should not leave the diaphragm in for more than 24 hours, however. This can increase the risk of toxic shock syndrome.

• Can a woman use lubricants with a diaphragm?

Yes, but only water- or silicone-based lubricants if the diaphragm is made of latex. Products made with oil cannot be used as lubricants because they damage latex. Materials that should not be used with latex diaphragms include any oils (cooking, baby, coconut, mineral), petroleum jelly, lotions, cold creams, butter, cocoa butter, and margarine. Oil-based lubricants will not harm a plastic diaphragm. Spermicides usually provide enough lubrication for diaphragm users.

• Do diaphragms help protect women from STIs, including HIV?

Research suggests that the diaphragm may help protect somewhat against infections of the cervix such as gonorrhea and chlamydia. Some studies have also found that it also may help protect against pelvic inflammatory disease and trichomoniasis. Studies are underway to assess whether incorporating a microbicide into the diaphragm would help to prevent HIV and other STIs. Currently, only male and female condoms are recommended for protection from HIV and other STIs.

• Is there a new diaphragm that does not require fitting?

Yes. The one-size SILCS diaphragm has been developed to fit most women without the need for a provider specifically trained to fit the diaphragm. Made of silicone, it can be easier to handle and more comfortable than conventional latex diaphragms. It is registered under the brand name Caya in 3 dozen countries. Used with a spermicidal gel, it offers similar protection to conventional diaphragms.