What is the best initial test for a patient with vaginal bleeding who suspects their Intrauterine Device (IUD) is displaced in the Emergency Department (ED)?

Best Test for Suspected Displaced IUD with Vaginal Bleeding in the ED

The best initial test for a patient with vaginal bleeding who suspects their IUD is displaced is a combined transabdominal and transvaginal ultrasound with Doppler. 1

Diagnostic Algorithm for Suspected Displaced IUD

Initial Assessment

• Combined transabdominal and transvaginal ultrasound with Doppler is the most appropriate first-line imaging study for patients with abnormal uterine bleeding and suspected IUD displacement 1
• This approach allows visualization of both the uterine cavity and potential locations of a displaced IUD, including:
  • Within the endometrial cavity (normal position)
  • Partially embedded in the myometrium
  • Located in the endocervical canal
  • Perforated through the uterine wall 2

Benefits of Ultrasound as First-Line Test

• Provides immediate visualization of IUD position relative to the uterine cavity 2
• Can identify malpositioned IUDs that may be causing symptoms (pain, bleeding) 3
• Non-invasive and readily available in most emergency departments 4
• Allows assessment of related complications such as bleeding source or fluid collections 2

Ultrasound Findings to Look For

• IUD location relative to the endometrial cavity 2
• Evidence of embedment into the myometrium (associated with higher rates of pain and bleeding) 3
• IUD positioned in the lower uterine segment or cervix 5
• Complete perforation with IUD located outside the uterus 6

Management Based on Ultrasound Findings

If IUD is Visualized in Abnormal Position

• A malpositioned IUD that is low-lying or extending into the cervix should be removed in the emergency department if strings are visible and can be safely retrieved 4
• Removal is particularly indicated when associated with persistent pelvic pain and vaginal bleeding 4, 3
• 75% of patients with abnormally located IUDs present with bleeding or pain compared to only 34.5% of those with normally positioned IUDs 3

If IUD is Not Visualized in Uterine Cavity

• When ultrasound shows an empty uterine cavity and the IUD is not visible, consider:
  • Expulsion (most common scenario)
  • Perforation with migration to peritoneal cavity 7
• Additional imaging may be required:
  • Abdominal X-ray (relatively inexpensive and non-invasive way to locate a perforated IUD) 7
  • CT scan or MRI if perforation with adjacent organ involvement is suspected 6

Special Considerations and Pitfalls

Common Pitfalls to Avoid

• Assuming normal IUD position despite symptoms - 16.8% of IUDs may have abnormal positioning that is only detectable with specialized imaging 3
• Missing partial embedment of IUD arms in the myometrium, which is associated with higher rates of bleeding (35.7% vs 15.1%) and pain (39.3% vs 19.4%) 3
• Deferring imaging in patients with prior cesarean deliveries, as uterine scars may facilitate IUD migration 6

When to Consider Advanced Imaging

• If the initial ultrasound is inconclusive, MRI of the pelvis without and with contrast is the next appropriate imaging study 1
• Three-dimensional ultrasound reconstruction provides superior visualization of IUD position and is more sensitive for detecting subtle malposition, particularly side-arm embedment 3, 2
• CT imaging may be necessary when perforation with migration to adjacent structures is suspected 6

Clinical Improvement After Intervention

• Studies show that 95% of patients with abnormally located IUDs report improvement in symptoms after IUD removal 3
• Prompt recognition and management of malpositioned IUDs can prevent unnecessary testing and delays in care 5