An intrauterine device (IUD) is a T-shaped piece of plastic inserted into the uterus for long-term, highly effective contraception. Attached to the IUD are one or two thin, flexible strings that extend through the cervix into the upper vagina. These strings allow a healthcare provider to remove the device and serve as a self-check mechanism, confirming the IUD remains correctly positioned high within the uterine cavity. If these strings cannot be felt, it is a common reason for concern and often prompts a call to a clinic.
Immediate Steps to Take
If you cannot feel the IUD strings, the immediate priority is preventing unintended pregnancy and seeking professional guidance. Stop attempting to locate the strings, as repeated probing could irritate the cervix or cause a partially displaced IUD to shift further. This brief pause prevents manipulation that might complicate professional retrieval. Until a healthcare provider confirms the IUD’s position and contraceptive reliability, use a reliable backup birth control method, such as condoms or spermicide. The IUD’s effectiveness cannot be guaranteed if its location is unknown. Contact your healthcare provider promptly to schedule an appointment to determine the cause of the missing strings.
Common Reasons for Unreachable Strings
The inability to feel the IUD strings often does not signify a serious problem but results from the device’s normal interaction with the body’s dynamic anatomy. The strings are intentionally trimmed short and tend to coil or curl up against the cervix. This coiling makes them temporarily difficult to locate during a self-check, even if the IUD is correctly placed in the uterus. Up to 18% of users may experience difficulty locating their strings at some point.
Changes in the position of the cervix throughout the menstrual cycle can also make the strings unreachable. For example, during ovulation, the cervix may sit higher, retracting the strings further into the endocervical canal. The strings may have also been cut shorter during the initial insertion procedure, making them inherently harder to feel. Furthermore, if the IUD has rotated slightly, the strings can be pulled higher or tucked into a fold of vaginal tissue, remaining safely in place but out of reach.
Potential Medical Outcomes and Risks
While many cases of missing strings are benign, they can also be the sole indication of IUD displacement or expulsion. Expulsion occurs when the IUD moves out of its correct position high in the uterus, either partially or completely, and this is most common in the first few months after insertion. A partial expulsion means the IUD has shifted but has not fully exited the uterus, significantly reducing its contraceptive efficacy.
If the IUD has partially or completely expelled without the patient noticing, the primary risk is an unintended pregnancy because the device is no longer providing reliable protection. Unnoticed expulsion may be suspected if a person with a hormonal IUD experiences a return to heavier or more painful menstrual bleeding, or if any portion of the IUD’s hard plastic is felt near the cervix. Expulsion rates typically range from 2% to 10% of users.
A rarer, serious complication is uterine perforation, where the IUD pushes into or through the wall of the uterus, typically occurring during insertion. This complication is reported in approximately 1 to 2 per 1,000 insertions. If perforation occurs, the IUD is no longer in the uterine cavity and cannot provide contraception. Perforation may not always present with noticeable symptoms, making the missing strings an important warning sign that warrants professional investigation.
Professional Examination and Management
A professional evaluation begins with a comprehensive pelvic examination, utilizing a speculum to visualize the cervix. The healthcare provider first looks for the strings at the external opening. If the strings are not visible, the next step is often using specialized, small instruments, such as a cytobrush or a thread retriever, to gently sweep the endocervical canal. This simple in-office procedure is frequently successful in snagging strings that have retracted or coiled just inside the cervix.
If the strings remain unlocated, the provider orders imaging to confirm the IUD’s location. A transvaginal ultrasound is the standard diagnostic tool, clearly showing if the IUD is situated correctly within the uterus. If the ultrasound confirms proper placement, the patient may be advised to leave the IUD in place. If the ultrasound does not show the IUD in the uterus, an X-ray of the abdomen and pelvis may be performed to check if the device has perforated the uterine wall and migrated into the abdominal cavity.
If the IUD is confirmed to be misplaced or partially expelled, it must be removed. Retrieval of an IUD with missing strings often involves using specialized grasping forceps or other instruments to access the device inside the uterine cavity. If the IUD is found to have migrated outside the uterus, surgical intervention may be necessary. Management depends on the IUD’s confirmed location and the patient’s desire for continued contraception.