An intrauterine device (IUD) is a highly effective form of long-acting reversible contraception placed inside the uterus by a healthcare provider. The T-shaped device has thin strings attached to the bottom, which are a frequent source of questions for users. Understanding their typical length and behavior is key to feeling confident about the device’s placement. This article clarifies the normal expectations for IUD string length and explains when a change might signal a need for medical attention.
The Purpose and Initial Placement of IUD Strings
The strings serve two primary functions: retrieval and placement confirmation. They are typically made of a thin, flexible plastic or nylon material, strong enough for removal but soft enough not to cause irritation. While not part of the contraceptive mechanism, they are necessary for a healthcare provider to remove the device when its lifespan is complete. Immediately following insertion, the provider trims the strings to an appropriate length, usually one to two inches (3 to 5 centimeters). This length allows the strings to extend out of the cervix and rest in the upper vagina, enabling the user to perform self-checks to confirm correct positioning.
Defining Normal String Length
The expected length after the initial healing period is the trimmed length, typically allowing one to two inches to be felt in the upper vagina. The strings should be consistently accessible for a user to feel during a monthly self-check. To check the strings, wash hands, squat or sit comfortably, and insert a finger until the firm cervix is located. The strings should be felt gently poking through the cervical opening. The perceived length can fluctuate slightly throughout the menstrual cycle. The cervix naturally moves lower during menstruation, making the strings feel longer, and moves higher during other parts of the cycle, making them feel shorter or difficult to find. This minor fluctuation is normal and relates to the natural repositioning of the cervix.
What Changes in String Length Indicate
A significant, noticeable change in string length from one month to the next can indicate that the IUD has shifted from its correct position. If the strings feel noticeably longer, this may signal a partial expulsion, meaning the IUD has begun to move out of the uterus. Since the IUD’s effectiveness depends on exact placement, a partial expulsion compromises its ability to prevent pregnancy. The opposite scenario is when the strings feel significantly shorter or cannot be located at all. In many cases, this is a benign event where the strings have simply curled up inside the cervical canal or high up against the cervix. However, shorter or missing strings can also indicate that the IUD has shifted, or, in very rare cases, that the device has perforated the uterine wall. If a user is unable to locate the strings, a healthcare provider must confirm the IUD’s location.
When to Seek Medical Attention
A person should contact a healthcare provider for an examination if the strings feel significantly longer or shorter than the established normal length, or if they cannot be located at all. Until proper placement is confirmed, it is recommended to use a backup method of contraception, such as condoms. Immediate medical attention is necessary if a user or their partner can feel the hard plastic or copper part of the IUD protruding from the cervix. Other warning signs include severe cramping, persistent pelvic pain, unexplained fever, or unusual vaginal discharge. These symptoms, especially when combined with a change in string length, suggest the IUD may be out of place or that an infection is present.