An intrauterine device (IUD) is a small, T-shaped piece of flexible plastic that a healthcare provider inserts into the uterus to provide long-acting reversible contraception. The device is located inside the uterus, but attached to its base are one or two thin threads, typically made of nylon or polyethylene, known as IUD strings. These strings hang down through the cervix and rest in the upper part of the vaginal canal. The strings allow a healthcare professional to gently remove the IUD when replacement is needed or contraception is no longer desired. They also allow the user to perform a monthly self-check to confirm the device remains correctly positioned.
How to Locate the IUD Strings
Checking for the presence of the IUD strings is a simple physical check that should be done once a month, ideally after the menstrual period has ended. Before beginning, wash your hands thoroughly with soap and water, ensuring cleanliness beneath the fingernails to minimize the introduction of bacteria. A comfortable position is important for a successful check, such as squatting down, sitting on the edge of a toilet, or propping one leg up on a stable surface.
Once positioned, gently insert your index or middle finger high into the vagina until you can feel the cervix. The cervix is the firm, rounded opening at the top of the vaginal canal and often feels rubbery, similar to the tip of your nose. If the strings are in the correct place, they should be felt protruding slightly from this opening.
The strings are usually cut to a length of about one to two inches from the cervix, and you should be able to feel them with the tip of your finger. Running your finger lightly across the surface of the cervix can help locate the fine threads. Consistent monthly checking helps the user become familiar with the normal positioning and feel of the strings, making it easier to detect subtle changes.
Interpreting What You Feel
When the IUD is correctly in place, the strings should feel like two fine, flexible threads, similar to soft fishing line or taut dental floss. Both strings should feel approximately the same length each time you check them, and they should be curling slightly near the opening of the cervix. Over the first few months after insertion, the strings tend to soften and may curl around the cervix, which is a normal change that can make them less noticeable.
A significant change in the length of the strings can signal a potential issue with the IUD’s position, indicating partial expulsion or migration. If the strings feel noticeably longer than usual, the device may have started to slip downward toward the cervix or into the vaginal canal. Conversely, if the strings suddenly feel much shorter or are missing entirely, the IUD may have moved higher up into the uterus, or the strings may have coiled up into the cervical canal.
Feeling the hard, plastic body of the IUD itself resting against the cervix or in the upper vagina is a serious finding. This sensation confirms that the device has partially expelled from the uterus and is no longer fully protected. Any abnormal sensation, or accompanying new symptoms like severe cramping or unusual bleeding, warrants immediate attention. Never tug or pull on the strings, even gently, as this could cause the IUD to shift or expel entirely.
Safety Steps If the Strings Are Missing or Shifted
If a self-check reveals that the IUD strings are missing or significantly shifted from your normal length, take immediate action. Assume the IUD is no longer providing reliable contraception and begin using a backup birth control method, such as condoms, right away. This precaution must be maintained until a healthcare provider can confirm the device’s correct placement.
Contact your healthcare provider’s office to schedule an appointment for a placement check, mentioning that you cannot locate the strings or that they have shifted. The provider will perform a pelvic exam, often using a speculum, to visually check the cervix for the strings. If the strings are still not visible, the next step usually involves a pelvic ultrasound to determine the IUD’s exact location within the uterus.
Missing strings can occur because they have coiled up into the cervical canal, which is not a cause for alarm if the device remains in the uterus. However, a shift can mean the IUD has partially or fully expelled, or it may have perforated the uterine wall. Until the IUD’s position is confirmed, avoid inserting anything into the vagina, including tampons, or engaging in intercourse without a barrier method.