A diaphragm is a reusable method of contraception. It is a device made of rubber or silicones, sometimes with a ring of metal, and it looks like a wide cup or hat.
This article is part of our Contraception Series!
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Note: the information below was sourced from references (1-5), unless stated otherwise.
What is it?
A diaphragm is a reusable method of contraception. It is a device made of rubber or silicones, sometimes with a ring of metal, and it looks like a wide cup or hat. The diaphragm is inserted over the cervix via the vagina. When inserted correctly, it also covers the area around the cervix, and closes off the upper part of the vagina more or less completely. To increase protection against pregnancy, a diaphragm is usually used in combination with spermicides. Read more about why this is and how they work below.
Because the diaphragm has to fit well to be effective, they’re only available on prescription in most areas. Your doctor will measure the space inside your vagina using model diaphragms. This requires a pelvic exam, in which the doctor looks and feels around the vagina and cervix using their fingers and a speculum. This can be uncomfortable, both physically and mentally. Let your doctor know if you’re nervous for the examination and procedure or if you’re uncomfortable at any time. If you lose or gain weight (about 3 kilograms [7 pounds] or more), or go through pregnancy (even if you miscarry or have an abortion), you should get your diaphragm refitted. Your diaphragm should be replaced every year or so. Check this with your healthcare provider.
In some regions, you can get a diaphragm in store or online. These typically come in sizes based on whether you’ve given birth or not.
Inserting a diaphragm has a bit of a learning curve. If you find it too difficult, you might be more inclined to skip it when you’re having sex. If that’s the case for you, a different method may be more suitable to keep your risk of pregnancy low. You could opt for a male or female condom or a hormonal method instead.
How does it work?
The diaphragm, like a condom, creates a physical barrier that prevents sperm cells from entering the uterus through the cervix. As mentioned above, it’s usually combined with a spermicide. A spermicide is a gel or cream that kills sperm cells or prevents them from moving around. It can also be used as a contraception method on its own, but it’s not very effective that way (read more about spermicides here). When used with a diaphragm, you should put the spermicide on the rim of the diaphragm and on the inside of the diaphragm (the side that goes over your cervix, not the side that will be exposed to a penis).
You can insert the diaphragm up to six hours before you expect to have sex. If you insert it more than two hours before you have sex, add some spermicide high up in the vagina (as if inserting a tampon) right before you have sex. Before you start using this method, you should carefully check the instructions provided to you by your doctor or on the packaging.
How do I use a diaphragm?
You should leave your diaphragm in place for at least six hours after the last time you had sex. This is the time needed for sperm cells to die in the acidic environment of the vagina. If you want to continue having sex or have sex again before the six hours have passed, put more spermicide in the vagina, but don’t take out the diaphragm. Start counting the six hours from then on again.
How effective is it?
The diaphragm (combined with a spermicide) is quite effective at preventing pregnancy. With perfect use, it’s 94% effective, meaning out of 100 people* using the diaphragm, 6 will get pregnant within a year. With typical use, this increases to about 12 out of 100 people* per year (meaning it’s 88% effective).
What are possible side-effects?
When used in combination with spermicides, the diaphragm can irritate the vagina. Moreover, if left in place for too long, there is a very small risk of toxic shock syndrome. For this reason, don’t leave your diaphragm in for more than 24 hours. You also have a higher risk of bladder infection (UTI) when using a diaphragm. Peeing within half an hour after sex is always important to prevent developing a bladder infection, but especially when you’re using a diaphragm. Lastly, and importantly, spermicides can increase the risk of transmission of HIV. If there is any chance you or your partner have HIV, use a condom.
When can't I use it?
Some people can’t use a diaphragm because they have a prolapse that’s too severe. If you have a prolapse, or a different issue with your pelvic floor, ask your doctor if a diaphragm would be suitable for you. The diaphragm also can’t be used in combination with an oil-based lubrication, because this damages the device’s material. Choose a water-based lubrication instead. The diaphragm shouldn’t be used if you have a high risk to catch HIV (or have an HIV infection), or if you have a history of toxic shock syndrome. In case you or your sex partners have a latex allergy, don’t choose a diaphragm containing latex.
Does it work immediately?
Usually, yes. When you’ve inserted the diaphragm with spermicide, you’re good to go. However, some spermicides take longer to work (read the box carefully to make sure), and you should insert more spermicide in the vagina if you inserted the diaphragm more than two hours before starting sex and if you have sex multiple times.
What happens to my fertility if I stop using it?
Since nothing in your body changes when you use this method, nothing’s different when you stop using this method. You have a higher risk of pregnancy if you’re having unprotected sex compared to when you’re using contraception.
Does it protect against sexually transmitted diseases (STDs)?
No. While the diaphragm may protect against some STDs, it doesn’t do so reliably. It doesn’t protect at all against some other STDs, including HIV. Therefore, if there is a risk you or your partner has an STD, use a condom instead.
*People, here, means anyone who is able to become pregnant, including girls, women, and non-binary people and transgender men who still have their uterus, vagina, and ovaries.
Are you curious about other methods to protect yourself from an unwanted pregnancy? Read about other birth control options here!
This article is pending medical review.
Contributors
Written by Juliëtte Gossens
Reviewed by Sophie Oppelt and Selina Voßen
Edited by Juliëtte Gossens
References
McFarlane I (ed.). Seeing the unseen: The case for action in the neglected crisis of unintended pregnancy. United Nations Population Fund. 2022. Available from: https://www.unfpa.org/sites/default/files/pub-pdf/EN_SWP22%20report_0.pdf
Hacker NF, Gambone JC, Hobel CJ (eds.). Hacker & Moore’s Essentials of Obstetrics & Gynecology. 6th ed. Philadelphia: Elsevier; 2016.
Hoffman BL, Schorge JO, Halvorson LM, Hamid CA, Corton MM, Schaffer JI (eds.). William’s Gynecology. 4th ed. New York: McGraw-Hill Education; 2020.
Centers for Disease Control and Prevention. The United States Medical Eligibility Criteria for Contraceptive Use, 2016 (US MEC). Available from: https://www.cdc.gov/reproductivehealth/contraception/mmwr/mec/summary.html
Centers for Disease Control and Prevention. 2016 U.S. Selected Practice Recommendations for Contraceptive Use (U.S. SPR). Available from: https://www.cdc.gov/reproductivehealth/contraception/mmwr/spr/summary.html
Please note: the information we provide to you here is for educational purposes only. If you’re experiencing any discomfort or have any complaints or questions about your health, please contact your doctor or other relevant health professional. We don’t provide medical advice.