An intrauterine device (IUD) is a small, T-shaped contraceptive device placed into the uterus for long-term birth control. While the idea of an IUD fragmenting or “breaking” inside the body is a common concern, modern IUDs are engineered with resilient materials. True, spontaneous fragmentation is extremely rare. Most complications that lead people to believe the IUD has broken involve the device shifting position, rather than fracturing.
IUD Design and Material Integrity
The physical integrity of an IUD is maintained through the use of flexible materials. The T-shaped frame is typically constructed from medical-grade polyethylene, a plastic polymer chosen for its resilience and biocompatibility with the uterine environment. Copper IUDs feature a fine copper wire wrapped around this frame, while hormonal IUDs contain a reservoir of synthetic progestin. These materials are selected to withstand the dynamic forces within the uterus, including muscle contractions associated with the menstrual cycle.
The likelihood of an IUD spontaneously fracturing while properly in place is very low, as the materials are not prone to degradation under normal uterine conditions. Fragmentation is an unusual complication, but it can happen, particularly with the copper component of non-hormonal IUDs, with a prevalence estimated at 1–2% of devices removed. Fragmentation of the copper coil may be linked to material fatigue, chronic inflammation, or, in rare cases, a reaction with certain bacteria, such as Actinomyces species. If a piece is found to be missing, it is typically discovered during a difficult removal procedure, not while the device is in use.
Device Displacement and Expulsion
The most common complication that leads people to suspect an issue with their IUD is movement within the uterus. Displacement occurs when the IUD shifts from its intended position at the top of the uterine cavity, often lying lower in the uterus, but remains entirely inside the organ. This shifting can make the device less effective at preventing pregnancy.
Expulsion is a more significant movement where the IUD partially or completely passes through the cervix and out of the uterus, which happens in an estimated 2–10% of users during the first year. Factors that increase the risk include IUD insertion immediately following childbirth, heavy menstrual bleeding, or possessing a uterus with a smaller-than-average cavity or structural irregularities like fibroids. Strong uterine contractions, particularly during menstruation, are a common mechanism for the device being pushed out of place.
Recognizing Signs of Complication
Recognizing the signs of a complication is important for timely management. One immediate indicator is a change in the IUD strings: they may feel shorter or longer than usual, or you may not be able to feel them at all. Persistent, severe cramping or pelvic discomfort not relieved by over-the-counter pain medication can also signal a problem, such as a displaced IUD or an embedded arm.
Other symptoms warranting immediate medical attention include abnormal vaginal discharge, especially if foul-smelling, which can indicate an infection like pelvic inflammatory disease (PID). You should also monitor for signs of systemic illness, such as fever or chills. If a sexual partner can feel the hard tip of the IUD during intercourse, this is a clear sign of partial expulsion.
Medical Management and Retrieval
If a complication is suspected, a healthcare provider will confirm the device’s location. An ultrasound is the standard diagnostic tool used to visualize the IUD and determine if it is correctly positioned within the uterine cavity. If the IUD cannot be located via ultrasound or if perforation is suspected, an X-ray can be used to see if the device has moved outside the uterus into the abdominal cavity.
Retrieval of a displaced or embedded IUD typically involves transcervical removal, often under ultrasound guidance using specialized forceps. In the rare event that the IUD has perforated the uterine wall and migrated into the pelvic or abdominal cavity, a surgical procedure, such as laparoscopy, is usually required to locate and remove the device. After removal, the healthcare provider will discuss replacing the device or selecting an alternative contraceptive method, taking into account the cause of the initial complication.