The diaphragm is a small, flexible cup made of silicone or latex that sits inside the vagina to prevent pregnancy. It's been used for centuries and can be up to 94% effective when used correctly. If you're considering the diaphragm for birth control, here's what you need to know.
How to Use a Diaphragm
Using a diaphragm is simple, but it does require a few steps:
Apply about a tablespoon of spermicide inside the cup and around the rim.
Find a comfortable position, fold the diaphragm in half, and insert it into your vagina as far back as it will go, making sure it covers your cervix.
Leave the diaphragm in for at least 6 hours after sex, but no longer than 24 hours.
To remove, hook your finger over the rim and gently pull it out.
Clean the diaphragm with soap and water, let it air dry, and store it in its case.
Remember to reapply spermicide before each time you have sex, even if the diaphragm is already in place.

Effectiveness of the Diaphragm
The diaphragm's effectiveness depends on proper use. When used perfectly, only 6 out of 100 women will get pregnant. However, with typical use, the rate is closer to 12 to 18 out of 100. While not as effective as some other methods like the IUD or birth control pills, it's still more effective than condoms or other barrier methods.
Pros and Cons of the Diaphragm
Pros:
You can use it even if your partner doesn't want to use a condom.
It doesn't affect your hormones.
You can put it in before sex, so it doesn't interrupt the mood.
It's easily reversible if you want to get pregnant.
Cons:
It doesn't protect against STDs.
You have to remember to reapply spermicide every time you have sex.
It can be messy to put in and take out.
You need a prescription from a doctor.
Is the Diaphragm Right for You?
The diaphragm might be a good choice if you want a hormone-free, easily reversible method of birth control and you're at low risk for STDs. However, you need to be comfortable inserting and removing it and be able to use it consistently and correctly. Talk to your healthcare provider to see if the diaphragm is right for you and to get a prescription.