IUD placement is checked in three main ways: you can feel for the strings yourself at home, your provider can look for the strings during a pelvic exam, or an ultrasound can confirm the device’s exact position inside the uterus. Most of the time, a simple string check is all that’s needed.
Checking the Strings at Home
The most common way to verify your IUD is in place is by feeling for the strings yourself. After insertion, two thin plastic strings hang down from the IUD through the opening of your cervix. To check them, insert a clean finger into your vagina and feel for your cervix at the top. It feels firmer than the surrounding tissue, often compared to the tip of your nose. You should be able to feel the strings coming out of the small opening in the center.
The strings sometimes wrap around the cervix, which can make them tricky to locate. That alone isn’t a concern. What you don’t want to feel is the hard, rigid end of the IUD itself poking through, which would suggest the device has shifted out of position. If you can’t find the strings at all or you feel the plastic body of the IUD, contact your provider.
What Your Provider Checks During a Visit
During a routine pelvic exam, your provider will use a speculum to look at your cervix and confirm the IUD strings are visible. This is quick and typically painless, since they’re only looking at the strings rather than manipulating the device. A bimanual exam (pressing on your abdomen while examining internally) may also be done to check for tenderness or anything unusual with the uterus.
The CDC’s 2024 contraceptive guidelines note that no routine follow-up visit is specifically required after IUD placement. Instead, providers are advised to check for the strings whenever you come in for other routine visits. If you’re having no symptoms, that casual check is generally sufficient.
When Ultrasound Comes Into Play
Ultrasound isn’t part of a routine IUD check for most people. It’s reserved for situations where something seems off: the strings can’t be found, you’re having unusual pain or bleeding, or there’s a concern the device has moved. A standard transvaginal ultrasound can show whether the IUD is sitting in the uterine cavity near the top of the uterus (the fundus), which is where it belongs.
Correct positioning means the IUD sits within about 3 millimeters of the fundus. If it’s farther away than that, providers consider it displaced. A displaced IUD most often ends up in the lower part of the uterus, which can cause abnormal bleeding, pelvic pain, and reduced effectiveness at preventing pregnancy.
In some cases, a standard two-dimensional ultrasound can miss subtler problems. Three-dimensional ultrasound produces a coronal view that shows the entire device and both of its arms within the uterine cavity. Research has found that abnormal positioning of the IUD’s arms, including cases where the device is partially embedded in the uterine wall, is only detectable on this 3D view. If you’re experiencing persistent pelvic pain or bleeding and a regular ultrasound looks normal, a 3D scan may be the next step.
What Happens If the Strings Are Missing
Missing strings don’t automatically mean something is wrong. The strings may have curled up inside the cervical canal, or they may have been trimmed short. But missing strings do trigger a specific diagnostic sequence because providers need to figure out where the device actually is.
The first step is usually a pelvic ultrasound, which locates the IUD inside the uterus in most cases. If ultrasound can’t find it, an abdominal X-ray can determine whether the device is still somewhere in the body. On rare occasions when an IUD has migrated outside the uterus entirely, a CT scan can pinpoint its exact location. These advanced imaging steps are uncommon, but they’re part of the standard protocol when an IUD simply can’t be found.
How Often IUDs Actually Move
Complete expulsion, where the IUD falls out entirely, happens in fewer than 5% of cases within the first year. Partial expulsion, where the device shifts but doesn’t fully come out, is more common, occurring in roughly 11 to 13% of cases in the first year after placement. The risk is highest in the first few months, which is why many people check their strings more frequently right after insertion and less often over time.
Signs Your IUD May Have Shifted
A displaced IUD often announces itself. The most common symptoms are abnormal bleeding and pelvic pain, sometimes described as a constant feeling of pressure with occasional sharp sensations triggered by changing positions. Nausea, lightheadedness, and headaches can also accompany displacement. Some people notice their strings feel longer or shorter than usual, or they can suddenly feel the hard body of the device at the cervix.
Pain alone doesn’t confirm displacement, since cramping is normal for the first few weeks after insertion. But pain that starts after an initial settling-in period, or that worsens rather than improves, is worth getting checked. Your provider can typically resolve the question with a quick string check or ultrasound in a single visit.