The IUD is a highly effective form of reversible contraception. When a user cannot feel the small threads, or strings, meant to confirm its placement, it often causes anxiety. Not feeling the strings raises the question of whether the IUD has shifted or is no longer providing protection. While this discovery warrants immediate attention from a healthcare provider, the absence of strings is not always an indication of a serious problem.
The Function of IUD Strings and When to Check Them
The IUD strings are thin, flexible plastic threads, often described as having the texture of fishing line, that extend a short distance out of the cervix into the upper vaginal canal. These strings allow the user to perform a monthly self-check to confirm the IUD remains correctly positioned inside the uterus.
For the healthcare provider, the strings are necessary for the safe removal of the device when it expires or when the user desires to stop using contraception. During insertion, the clinician trims the strings to minimize discomfort during daily activities or intercourse. Self-checks are recommended once a month, often after menstruation, when the cervix sits lower and the strings may be easier to reach.
The proper technique involves washing hands thoroughly and inserting a clean finger until the firm, rubbery cervix is located. The strings should be felt gently poking through the opening of the cervix. The goal is simply to confirm they are present and feel the same length as before, without pulling on them.
Common Reasons Why Strings May Be Absent
The inability to feel the IUD strings is common, affecting up to 18% of users. The most frequent reason is also the most benign: the strings have simply curled up. The flexible threads can retract into the cervical canal or coil around the cervix, making them impossible to feel. In this scenario, the IUD remains correctly positioned and continues to function as intended.
A more serious possibility is the partial or complete expulsion of the device, meaning the IUD has shifted or fallen out of the uterus. Expulsion typically occurs within the first year of use. It can be complete (falling out unnoticed) or partial (protruding through the cervix). If the IUD has moved out of place, contraceptive protection is compromised, requiring the immediate use of a backup birth control method.
The least common, but most serious, cause is uterine perforation, where the IUD moves through the uterine wall into the abdominal cavity. This complication is rare, occurring in approximately one to two out of every 1,000 insertions. Perforation is sometimes associated with severe pelvic pain or abnormal bleeding, and the device is considered translocated, pulling the strings entirely out of the vaginal canal.
Immediate Steps to Take After Not Feeling Strings
The first step after not feeling the strings is to remain calm, as retraction is the most likely cause. Gently re-check the position at a different time, perhaps after changing body positions, such as squatting or standing with one leg raised. Since the cervix position changes slightly during the menstrual cycle, this may bring the strings back into reach.
If the strings remain absent after a second check, assume the IUD is no longer providing contraceptive protection. Until a healthcare professional confirms the IUD’s correct placement, use a reliable barrier method of contraception, such as condoms, or abstain from intercourse. This ensures protection against unintended pregnancy while the device’s location is investigated.
Contacting the healthcare provider—an OB-GYN or a clinic—should be the next priority to schedule a prompt evaluation. Avoid attempting to locate the strings with instruments like tweezers or any other item inserted into the vagina. Doing so risks introducing infection or inadvertently moving the IUD further out of position, which could cause injury.
What Happens During a Clinic Evaluation
When a person presents with missing IUD strings, the clinician first performs a pelvic examination. This involves using a speculum to visualize the cervix and manually feeling for the strings around the cervical opening. If the strings are not immediately visible, the clinician may use a specialized tool, such as a cytobrush or an IUD retrieval hook, to gently probe the cervical canal.
This technique aims to sweep the endocervical canal (the passage between the vagina and the uterus) in case the strings have coiled up inside. If these simple, in-office methods are unsuccessful, the next step is medical imaging to determine the IUD’s location. A transvaginal ultrasound is the preferred first-line tool, confirming if the IUD is correctly seated within the uterine cavity, partially expelled, or absent from the uterus.
If the ultrasound cannot locate the IUD within the uterus, an abdominal X-ray may be ordered to check for perforation and migration. Since the IUD contains material visible on X-ray, the provider can determine if the device has moved through the uterine wall into the abdominal or pelvic cavity. Based on imaging results, the clinician will either leave the IUD in place if correctly positioned, or proceed with removal if it is expelled, migrated, or requires replacement.