Feeling your IUD strings is completely normal. After an IUD is placed, thin strings are left hanging through the cervix into the upper vagina, specifically so you can check that the device is still in position. These strings are typically trimmed to about 3 to 4 centimeters long, and reaching them with your finger during a self-check is exactly what’s supposed to happen.
What the Strings Are and Why They’re There
Every IUD has two thin threads attached to its base. Though there are two, they usually feel like a single thread when you touch them. The strings serve two purposes: they let you confirm the IUD hasn’t moved, and they give your provider something to grasp when it’s time for removal.
Right after insertion, the strings can feel somewhat stiff or wiry. Over time, they soften and tend to curl up against the cervix, making them less noticeable. In the first few weeks, you’re more likely to notice them because they haven’t had time to soften yet.
How to Do a Proper String Check
Checking your strings at home is straightforward. Wash your hands, then either squat down or prop one foot up on the edge of a bathtub. Insert your longest finger (usually your middle finger) all the way into your vagina until you reach your cervix at the top. The cervix feels firm, similar to the tip of your nose. Run your fingertip across it in different directions and you should feel the strings.
What you’re feeling for is consistency. The strings should feel roughly the same length each time you check. You should not be able to feel anything hard or plastic poking through the cervix. If you can feel a hard plastic edge, that’s the base of the IUD itself, which could mean the device is partially expelling.
What’s Normal vs. What Isn’t
Normal: feeling thin, soft threads against your cervix. Also normal: the strings feeling slightly different depending on where you are in your cycle, since the cervix shifts position throughout the month. Sometimes the strings tuck up around the cervix and are harder to find, then become easy to feel again a few days later.
Not normal: strings that suddenly feel much longer or shorter than usual, feeling the hard plastic bottom of the IUD coming through the cervical opening, or not being able to find the strings at all after previously feeling them consistently. These changes can signal that the IUD has shifted. The expulsion rate for IUDs in the first year is 2 to 10%, so while uncommon, it does happen. A study of over 700 IUD placements found that about 17% were malpositioned within eight weeks, though only about half of those needed removal.
When Strings Feel Longer or Shorter Than Before
If the strings suddenly feel longer, the IUD may be sitting lower in the uterus than it should. If they feel shorter or you can’t find them at all, a few things could have happened. The strings may have simply curled up inside the cervical canal, which is the most common explanation and isn’t dangerous. Less commonly, the IUD could have shifted upward in the uterus, or in rare cases, perforated through the uterine wall.
When strings go missing, providers typically start by using a small brush to sweep the cervical canal, since the threads are often just tucked inside. If that doesn’t locate them, an ultrasound confirms whether the IUD is still in the right place. A pregnancy test is also standard at that point. If the ultrasound shows the IUD sitting correctly, there’s nothing further to worry about even if you can’t feel the strings yourself.
If you can’t feel your strings, use a backup method of contraception until a provider confirms the IUD is properly positioned.
Can Your Partner Feel Them Too?
Most partners don’t notice the strings during sex. Occasionally, though, a partner can feel them, particularly in the first weeks after insertion when the strings are still stiff. This tends to resolve on its own as the strings soften over time. If it remains bothersome, a provider can trim the strings shorter. Interestingly, trimming them very short can sometimes make the problem worse, because shorter strings stick straight out rather than curling flat against the cervix. Your provider can advise on the right length.
Signs That Need Prompt Attention
A routine string check that feels the same as last month is purely reassuring. But certain symptoms alongside a string change warrant a call to your provider: persistent lower abdominal pain that doesn’t respond to painkillers, sudden sharp pelvic pain, fever, unusual or foul-smelling discharge, very heavy bleeding, or any possibility of pregnancy. These could point to infection, perforation, or a displaced device, all of which are uncommon but treatable when caught early.
Perforation is rare, occurring in roughly 1 to 2 out of every 1,000 insertions. When the strings themselves perforate through the cervix (even rarer), it’s typically painless and discovered incidentally during a routine exam.