What causes an intrauterine device (IUD) to become displaced?

Contraceptive intrauterine device (IUD) displacement—also referred to as IUD malposition or migration—occurs when the device moves from its optimal location in the uterine cavity. A correctly placed IUD should sit centrally within the fundal region of the uterus, with its arms fully expanded and the strings visible at the external cervical os. Displacement may involve partial or complete expulsion (where the IUD descends into the cervical canal or protrudes through the external os), lateral or downward migration within the uterine cavity, embedding into the myometrium (partial or complete embedment), or, rarely, perforation through the uterine wall into the abdominal cavity.

Risk factors for IUD displacement include recent insertion (especially within the first 3–6 months), postpartum or postabortal placement, uterine anomalies (e.g., bicornuate or septate uterus), heavy menstrual bleeding, young age (<20 years), nulliparity, and vigorous physical activity shortly after insertion. Symptoms may be absent in mild cases; however, warning signs include increased or irregular vaginal bleeding, dysmenorrhea, dyspareunia, or inability to palpate the retrieval strings during self-check. In cases of perforation or intraperitoneal migration, patients may present with acute abdominal pain, signs of peritonitis, or complications such as bowel adhesions or obstruction—though these are exceedingly rare.

Diagnosis relies on clinical assessment combined with imaging: transvaginal ultrasound is the first-line modality, offering high sensitivity for detecting position, embedment, or perforation. If ultrasound findings are inconclusive—or if intraperitoneal migration is suspected—pelvic MRI or contrast-enhanced CT may be warranted. Confirmation of correct IUD placement should always occur within 4–6 weeks post-insertion, especially in high-risk individuals.

Management depends on the degree and type of displacement. Asymptomatic, minimally displaced IUDs with intact strings and no evidence of embedment or perforation may be monitored conservatively with repeat imaging. Symptomatic or significantly malpositioned devices typically require removal—often via outpatient hysteroscopy for embedded or intracavitary malpositions, or laparoscopy for confirmed intraperitoneal migration. Removal should be performed by a clinician experienced in IUD management to minimize risk of further injury. After removal, alternative contraception should be offered promptly, and reinsertion—only if clinically appropriate—should follow established guidelines and patient counseling.