An intrauterine device (IUD) is a highly effective, small, T-shaped contraceptive device placed inside the uterus for long-term birth control. Thin, plastic threads, called IUD strings, extend from the device through the cervix and into the top of the vagina. These strings allow a healthcare provider to remove the device and serve as a way for the user to confirm the IUD remains in place. If these strings cannot be felt, it naturally causes concern about the device’s continued protection.
Proper Technique for Checking IUD Strings
Checking for the strings requires a systematic approach. Start by washing your hands thoroughly to prevent introducing bacteria into the vagina. Finding a comfortable position, such as squatting or sitting on a toilet with one leg up, helps shorten the vaginal canal and makes the cervix easier to reach.
Gently insert your index or middle finger into your vagina until you feel the firm, rubbery texture of your cervix, which feels similar to the tip of your nose. Feel for one or two thin threads protruding from the opening. The strings should feel like short pieces of fine fishing line or taut dental floss; compare their length and position to previous checks. Avoid pulling on the strings, as this could accidentally dislodge the IUD.
Everyday Reasons You Can’t Feel the Strings
The most frequent reasons for an inability to feel the strings relate to the strings’ position, not a problem with the IUD itself. Over time, the strings often soften and naturally curl up or coil around the cervix, tucking themselves into the endocervical canal. This makes them difficult or impossible to locate.
The position of the cervix also shifts throughout the menstrual cycle, affecting string accessibility. During ovulation, the cervix often moves higher and becomes softer, potentially pulling the strings out of reach. Conversely, the cervix tends to sit lower during menstruation, which is why checking after your period often makes the strings easier to find. If your healthcare provider trimmed the strings very short during insertion, they may simply be too short to reach consistently.
When Missing Strings Signal a Problem
While a simple change in string position is the most common cause, the absence of strings can also indicate a medically significant issue. The IUD may have undergone partial or full expulsion, meaning the device is moving out of the uterus. Expulsion is most likely to occur in the first few months after insertion, sometimes accompanied by symptoms like severe cramping, unusual vaginal discharge, or heavier-than-normal bleeding.
The IUD may also have shifted out of its correct placement within the uterine cavity, known as displacement or malposition. This shift can decrease the IUD’s contraceptive effectiveness. If you can feel the hard, plastic T-shape of the device itself, or if the strings feel significantly longer or shorter than usual, it suggests the IUD has moved.
In rare instances, the missing strings may signal uterine perforation, where the device has pushed through the wall of the uterus. Perforation is a serious complication that typically occurs at the time of insertion, affecting about one in every thousand placements. While often asymptomatic, symptoms can include persistent abdominal or pelvic pain and abnormal bleeding. If a healthcare provider cannot locate the IUD in the uterus via ultrasound, an X-ray may be used to determine if it has migrated into the abdominal cavity.
Immediate Action Steps
If you cannot feel your IUD strings, or if they feel notably different, take immediate steps to ensure your health and contraceptive protection. The first action is to begin using a non-IUD barrier method, such as condoms, for all intercourse, as the device may no longer be effective. Do not rely on the IUD for contraception until its correct placement is confirmed by a medical professional.
Contact your healthcare provider right away to schedule an examination. If you are sexually active and have not used a backup method, a pregnancy test may be necessary. During the appointment, the provider will first attempt to locate the strings using a speculum and potentially a small brush to sweep the endocervical canal. If the strings remain elusive, an ultrasound will be performed to visualize the IUD and confirm it is safely positioned within the uterus.