Cervical cap: How to use, effectiveness, and side effects

What is a cervical cap?

A cervical cap is a small dome-shaped cap that you insert into your vagina before sex to prevent pregnancy. Caps have a wide brim, with a dome or bowl in the center of the cup, and they have a strap across the middle of the dome or bowl, to make them easier to remove.

The cap covers the cervix, and is very similar to the diaphragm, although the cap is smaller, so it fits more snugly over your cervix.

How do cervical caps work?

Cervical caps fit over the cervix to create a physical barrier that prevents sperm from reaching your uterus. If sperm can’t get past the cap to reach an egg cell, then they’re unable to fertilize an egg – meaning you won’t get pregnant. 

Like diaphragms, cervical caps should be used with spermicide to make them more effective. Spermicide is a substance that immobilizes and kills sperm – so if any sperm do make it past the barrier of the cap, the spermicide should render them immobile, so pregnancy is still prevented. The cap should fit tightly over your cervix, keeping the spermicide in place.

You can insert a cervical cap several hours before having sex, but if you’ve left it in place for more than three hours beforehand, you should apply more spermicide. After sex, you should leave it in place for at least six hours. That gives the spermicide enough time to do its job and kill any sperm cells that have managed to get through. You can leave it in place for up to 48 hours.

Effectiveness of cervical caps

Cervical caps are more effective for women who’ve never given birth vaginally. That’s because your cervix and vagina are stretched during childbirth, and the cap might not fit as well after giving birth. That’s also why it’s so important to have your cap properly fitted by your doctor or healthcare provider before you start using it.

If you’ve never given birth, the cervical cap is 86% effective. That means that, for every 100 people who use the cap as their primary method of birth control, 14 will get pregnant in a year.

If you have given birth, the cervical cap is 71% effective, meaning that 29 women out of every 100 who use the cap will get pregnant in a year.

As with any form of birth control, the cap is most effective if you use it as instructed. That means it’s important to always use it as intended, including:

• Using the correct size
• Inserting it properly
• Making sure it covers your cervix
• Using spermicide
• Leaving it in place for at least six hours after sex
• Always remembering to use it when you have sex.

Cervical caps vs diaphragms

While these methods are both silicon-based barrier methods and work in a similar way, they are a little different. The cervical cap is more hat-shaped, while the diaphragm looks like a little bowl. The cervical cap tends to be smaller than the diaphragm and has the added advantage of being able to remain in place for longer. However, a diaphragm may be a better option if you’ve previously given birth, as the cap becomes less effective after childbearing.

These are all factors to consider when you choose your new birth control, and it’s a good idea to consider which option will suit you best, and discuss the benefits and drawbacks of each with your healthcare provider. 

How to insert a cervical cap

It can take a little trial and error to get the hang of inserting your cervical cap, but once you’ve practiced a few times, it should be easy enough. To insert your cervical cap:

• Wash your hands thoroughly
• Put a small amount of spermicide on the cup, spreading it across the flat part of the brim
• Put a small amount of spermicide in the groove between the brim and the dome
• Get into a comfortable position – some people like to stand with one foot on a chair or the toilet, while others find it more comfortable to lie down or squat
• Hold the cervical cap with the dome side up, then fold it in half and bring the edges together
• Insert the folded cap into your vagina, with the strap facing down
• Push the cap deep into your vagina until it covers your cervix
• Run your finger around the rim of the cap to ensure that it lies flat against the cervix and is well-positioned. It should feel secure and cover the cervix entirely.

Your doctor or healthcare professional will show you how to insert your cap, and there will be instructions in the packet, too if you forget. It shouldn’t feel uncomfortable or painful when it’s in place.

How to remove a cervical cap

Removing your cervical cap is generally much easier than inserting it. To remove it, you should:

• Thoroughly wash your hands
• Squat down
• Gently insert your finger into your vagina until you can feel the cap
• Push against it to release the suction
• Hook your finger around the strap and gently remove the cap

Once you’ve removed it, you should wash the cap with soap and warm water, then leave it to air dry. Regularly check the cap for any signs of damage, including tears and holes. If you’re unsure, you could even fill the cap with water to check for leaks.

Store your cervical cap according to the instructions provided, usually in its case or container away from extremes of temperature.

Advantages of the cervical cap

Every method of birth control has its advantages and disadvantages. The advantages include:

• It’s hormone-free: Unlike hormonal methods such as birth control pills, patches, or injections, the cervical cap does not introduce additional hormones into the body. So, if you don’t want to or can’t use hormonal birth control, the cap could be a good option for you.
• No side effects: Because it’s non-hormonal, the cervical cap also doesn’t have side effects.
• On-demand use: You can insert the cap a couple of hours before sex, so it doesn’t interrupt you in the moment.
• It’s reusable: Unlike some other barrier methods like condoms, you can use the cap again and again, this can make it cost-effective and reduce waste (each cap can be used for up to a year)
• They put you in control: You’re in charge of your birth control with a cap and you don’t need to rely on your partner. Because they’re non-hormonal, they also don’t affect your fertility, so if you decide you want to try to get pregnant, simply don’t use the cap and your fertility won’t be affected.

Disadvantages of the cervical cap

Of course, there are also downsides to this form of birth control. When you’re choosing the right option for you, it’s important to be aware of all the potential ups and downs.

• It may interrupt sex: While you can insert it a couple of hours before sex, if you’re more spontaneous, it could interrupt sex – which may make some people less likely to use it when they’re in the moment.
• You have to use it every time: You do need to use the cap every time you have sex, and you have to remember to use spermicide, too. If you’d prefer a longer-lasting form of birth control, you may want to consider an alternative, like the implant or IUD instead.
• No protection against STIs: Cervical caps aren’t effective against sexually transmitted infections.
• Some people have a bad reaction to spermicide: This must be used with a cervical cap for it to be effective.

Who can use a cervical cap?

Most people can use a cervical cap safely. However, it’s not recommended for certain people. It might not be right for you if:

• You’ve given birth or had an abortion recently
• It’s hard to find your cervix, or it’s in an unusual position
• You’ve had cervical cancer
• You’ve previously had toxic shock syndrome
• You’ve had surgery on your cervix or vagina

You also shouldn’t use a cervical cap when you’re on your period, as it may increase the risk of toxic shock syndrome. You should use an alternative form of birth control, like condoms during your period instead.

If you’re unsure whether the cervical cap is the right method of birth control for you, speak to your doctor or healthcare provider, who’ll be able to help you decide.

Finding the right birth control method for you

Birth control is a very individual choice, and the cervical cap may or may not be the right method for you. There are lots of different factors to consider when it comes to choosing contraception, from its effectiveness, to side effects, to family planning and lifestyle choice – but the most important thing is that we all have access to a multitude of birth control methods, and have the information we need to make an informed choice.

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