An intrauterine device (IUD) is a highly effective form of birth control, a small T-shaped device placed inside the uterus to prevent pregnancy. Thin, plastic strings are attached to the IUD and extend through the cervix. Users are meant to check these strings regularly to confirm the device is still in its correct position. When a person suddenly cannot feel the strings, it often causes immediate concern about the device’s effectiveness.
The Core Question: Missing Strings and Pregnancy Risk
The inability to feel your IUD strings does not automatically mean you are pregnant, but it signals that your device may no longer be positioned correctly. The primary risk is expulsion, where the IUD moves partially or completely out of the uterus. Although expulsion rates are generally low, this compromises the IUD’s protective function and significantly increases the risk of unintended pregnancy.
If the IUD has shifted but not fully expelled, its effectiveness is reduced because it may no longer properly inhibit fertilization or implantation. This means the person is exposed to pregnancy risk since the device is no longer a reliable contraceptive. The concern is further heightened because a pregnancy that occurs with an IUD still in place carries an increased risk of complications, including ectopic pregnancy.
In rare cases, missing strings can signal an early, unrecognized pregnancy. As the uterus grows, the strings can be drawn up into the uterine cavity, making them unreachable. Since IUDs are over 99% effective but not 100%, a pregnancy test should be the first step to address this possibility.
Common Reasons for Missing IUD Strings
The most frequent reason for missing strings is simple retraction or curling, not expulsion. The strings can coil up against the cervix or draw slightly into the endocervical canal. The position of the cervix naturally changes throughout the menstrual cycle, which can cause the strings to be temporarily out of reach. If the IUD remains correctly seated in the uterus, it will continue to function as intended, even if the strings are not accessible.
Strings may also be difficult to locate if they were cut very short during insertion. As the cervix shifts throughout the month, these short strings may become impossible to feel. This scenario is generally not a cause for concern regarding contraceptive efficacy, as the IUD is still likely in the correct position.
The more serious, though less common, reason for missing strings is the partial or complete expulsion of the device. This occurs when the uterus pushes the IUD out, which can happen without the person noticing the device fall out. Expulsion is more likely in the first few months after insertion. It is sometimes accompanied by symptoms like severe cramping, irregular bleeding, or a change in menstrual flow.
Immediate Steps When Strings Cannot Be Felt
The first immediate step when you cannot feel the strings is to re-attempt the check using the correct technique. Wash your hands thoroughly, find a comfortable position, and insert a finger to feel for the firm cervix and the thin strings. If a second, careful check confirms the strings are truly missing, you must take the following steps:
- Immediately take a home pregnancy test. A negative result rules out one major complication and provides time-sensitive information for follow-up care.
- Use a backup method of contraception, such as condoms, during any sexual intercourse. This protects against unintended pregnancy if the IUD has been expelled or is ineffective.
- Avoid placing anything into the vagina that could potentially dislodge a partially expelled device, including tampons or menstrual cups, until the IUD’s location is confirmed.
- Schedule an appointment with a healthcare provider without delay. Using a backup method and making the appointment provides a safe bridge to professional evaluation.
What Happens Next: Medical Evaluation and Follow-Up
When you see a healthcare provider, the initial step will be a physical examination to search for the strings. The provider will use a speculum to visualize the cervix. They may use a long, thin instrument, such as a cytobrush, to gently sweep the endocervical canal. This simple procedure is often successful in locating strings that have merely curled up into the cervix.
If the strings are not found during the physical exam, the next step is typically an ultrasound. This imaging technique is the standard method for confirming the IUD’s location, showing if it is correctly positioned within the uterus, has moved into the cervix, or is absent. Both transvaginal or transabdominal ultrasounds provide clear images of the device’s relationship to the uterine walls.
If the ultrasound cannot locate the IUD within the uterus, an abdominal X-ray may be ordered to check for the rare possibility of uterine perforation. If the IUD is determined to be misplaced or partially expelled, the provider will discuss the process for retrieval, which may involve specialized instruments. If the IUD is confirmed to be correctly in place, you may simply continue its use, often with a recommendation for an annual ultrasound check instead of self-checking the strings.