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Thanks to their reusable design, menstrual cups are a popular period product nowadays.

But if you have an intrauterine device (IUD), you may be worried about using one after hearing stories online about cups “sucking” out IUDs.

Rest assured that if you use your menstrual cup in the right way, there should be little chance of this happening.

Keep reading to find out how.

“Yes, you can use a menstrual cup if you have an IUD,” says Dr. Eleanor Rayner, an obstetrician, gynecologist, and founder of The Maternity Collective.

“Similar to a tampon, a menstrual cup sits inside the vagina, whereas your IUD sits inside the uterus,” explains Rayner. “It won’t interfere with your IUD working.”

However, the Faculty of Sexual and Reproductive Healthcare recommends that you wait at least 6 weeks after IUD insertion before you start using one.

The field of contraception is often light on research.

So, it’s unsurprising to hear that there haven’t been many studies on the link between menstrual cups and IUDs moving (displacement) or falling out (expulsion).

“Research previously showed there was no increased risk of expulsion with a menstrual cup,” says Rayner. “However, more recent research has suggested there might be.”

A 2012 survey of 930 people who had IUDs and used menstrual protection found “no evidence” of higher rates of early IUD expulsion in people who used menstrual cups during the first 6 weeks after insertion.

On the other hand, a 2-year 2020 study showed “higher than expected IUD expulsion rates” in menstrual cup users.

“Copper IUD users should be cautioned that concurrent menstrual cup use increases the risk of IUD expulsion and expulsion risk continues with ongoing menstrual cup use,” wrote the study authors.

But as other factors like age and heavy menstrual bleeding can lead to IUD expulsion, there is still the need for more long-term research.

According to Rayner, “expulsion or displacement with a menstrual cup could occur when you come to remove the cup and if the strings were to be pulled during the process.”

This appears to be backed up by small 2019 case studies in which seven IUD expulsions were linked to menstrual cup use.

The same small 2019 case studies showed that each of the subjects reported accidentally pulling or pinching the IUD strings while removing their menstrual cups.

The authors of the case studies noted that, as well as pulling on the strings, the suction of the menstrual cup may be responsible for dislodging the IUD.

Others, however, believe that the suction isn’t strong enough to move the device.

Speaking with your doctor or another member of your healthcare team about any concerns is the best first step.

They can then advise you on the best form of IUD and menstrual hygiene for your body.

For example, according to Planned Parenthood, hormonal IUDs can make periods lighter or make them go away completely, meaning you may not need to use period products as much or at all.

The position of your cervix can be important too, notes Dr. Deborah Lee, sexual and reproductive healthcare specialist for Dr. Fox Online Doctor and Pharmacy.

“If the cervix is low lying in the vagina, this makes it much easier to inadvertently dislodge the IUD threads when inserting or removing [a Mooncup],” she says.

Other menstrual cup brands, however, may sit differently inside your vagina.

You can also ask your doctor to cut the IUD strings shorter before insertion, reducing the risk of catching them.

Experts advise that you should wait awhile before using a menstrual cup. So, you’ll need to use alternative period products in the meantime.

“The rate of expulsion is greater in the first 6 weeks after insertion of an IUD,” explains Rayner. “Therefore, it’s recommended to wait at least 6 weeks after insertion before using a menstrual cup.”

The National Health Service recommends waiting even longer —at least 3 months.

“In the general population, the highest chance of expulsion of the IUD is in the first 3 months after fitting,” notes Lee.

If you’re not sure how long to wait, ask the healthcare professional who fitted your IUD. They can advise you on next steps.

Firstly, get to know your body. Your doctor or nurse should have advised you how to feel for your IUD strings.

So, a few days after insertion, feel inside your vagina for a firm mass —that’s your cervix. The strings should be coming out of your cervix.

Note that the position of your cervix tends to change throughout your menstrual cycle. So, try to get an idea of where it is during each stage.

This will help you correctly insert your menstrual cup.

Although most menstrual cups are designed to sit low down and away from the cervix, people with a low cervix may find that the cup’s much closer to the IUD strings.

If this is the case, check that the strings aren’t in the way during menstrual cup insertion.

When it comes to removing the cup, you’ll need to ensure the strings are either inside the cup or completely out of the way — you don’t want them caught between the cup and the wall of your vagina.

Then, you’ll need to break the seal —in other words, release the suction to avoid unnecessary pressure.

Some cups come with a tab that you pull down on before removing. Others will require you to pinch the base as if you were trying to fold the cup.

Finally, you’ll need to check your IUD strings.

“If you use an IUD for contraception, you should check the threads once a month, just after a period, as this is the time when it is most likely to fall out,” says Lee.

To do that, wash your hands, and sit or squat. Insert your finger into your vagina until you feel your cervix. Then, see if you can feel the strings hanging through.

Remember that if you’ve had your strings cut short, you may not be able to feel them.

The most obvious sign of IUD expulsion is seeing your IUD inside your menstrual cup. So, remember to check your cup after removing it.

Another thing to look for is a change to your IUD strings, whether that’s not being able to feel them at all or noticing that they feel shorter or longer.

Being able to feel the actual IUD is a sign that it could have moved, as are severe cramping and abnormal bleeding symptoms.

If you notice any of the above, book an appointment with a doctor straight away so they can see if the IUD has displaced or fallen out.

If you’re using the IUD for birth control, you’ll also need to use an alternative form of contraception and may need to consider emergency contraception, too.

A healthcare professional or a member of the care team at a sexual health clinic should be able to help with this.

You’re free to use any period product that you feel comfortable with.

Menstrual discs tend to use less suction than a menstrual cup, so they may alleviate any worries you have.

Tampons are another alternative. Although some feel they, too, come with IUD risks, a 2012 survey, and a 2019 survey didn’t find any links between the two.

(Just wait at least a month after IUD insertion before using tampons to reduce the risk of infection.)

If you’re really concerned, pads and period underwear have zero risk of dislodging an IUD.

Yes, there’s a *potential* link between menstrual cup use and IUD displacement or expulsion. But a lot more research is needed before experts advise against using menstrual cups.

Right now, it’s perfectly safe to use a cup if you have an IUD. Just ask the healthcare professional who fitted your IUD about how long you should wait before first use.

And, for peace of mind, remember to regularly check the strings (if applicable) and be careful when inserting and removing.

Lauren Sharkey is a U.K.-based journalist and author specializing in women’s issues. When she isn’t trying to discover a way to banish migraines, she can be found uncovering the answers to your lurking health questions. She has also written a book profiling young female activists across the globe and is currently building a community of such resisters. Catch her on Twitter.