What to do if intrauterine device (IUD) strings are not visible?

Management of Non-Visible IUD Strings

If IUD strings are not visible, perform or refer for ultrasound examination to determine the location of the IUD, as the device may still be in the uterus, may have been expelled, or may have perforated the uterine wall. 1

Initial Assessment Algorithm

When IUD strings cannot be visualized at the cervical os, follow this systematic approach:

Step 1: Attempt Gentle String Retrieval

• Use a cytobrush or cotton swab to gently probe the cervical canal to locate strings that may have retracted 2
• If strings can be safely retrieved from the cervical canal, document their presence and position 1

Step 2: Ultrasound Evaluation

• Transvaginal ultrasound is the first-line imaging modality to locate the IUD 3
• Ultrasound will determine if the IUD is:
  • Properly positioned in the uterine cavity
  • Malpositioned (low-lying, embedded, or displaced)
  • Absent from the uterus (suggesting expulsion or perforation) 1, 3

Step 3: If Ultrasound Shows Empty Uterus

• Obtain an abdominal X-ray to rule out uterine perforation, as this is a relatively cheap and non-invasive method to locate an IUD that has perforated into the peritoneal cavity 4
• Do not assume expulsion without imaging confirmation, especially if the patient has abdominal pain 5, 4

Management Based on IUD Location

IUD Confirmed in Uterine Cavity (Strings Retracted)

• If the IUD is properly positioned and the patient is asymptomatic, the device can remain in place 1
• Advise the patient to return promptly if she develops heavy bleeding, cramping, pain, abnormal vaginal discharge, or fever 1
• The patient will not be able to check for string presence herself; schedule regular follow-up visits 6
• String visibility is particularly lower after cesarean section insertion (72.4%) compared to vaginal insertion (98.1%) 6

IUD Malpositioned (Low-Lying or Embedded)

• Remove the IUD as soon as possible if it is low-lying, extending into the cervix, or embedded in the myometrium, especially when associated with pelvic pain 7, 8
• The CDC recommends removal without requiring updated ultrasound if previous imaging confirmed malposition and the patient has persistent symptoms 7
• Remove by gently pulling on strings if visible, or use specialized instruments or imaging guidance for embedded devices 8
• Do not replace the IUD on the same day due to increased risks of pain, bleeding, infection, and reduced contraceptive efficacy 8
• Wait at least 4-6 weeks before considering reinsertion to allow myometrial healing 8

IUD Perforated Through Uterine Wall

• An IUD that has perforated the uterus must be removed as soon as possible 8
• Laparoscopic removal is typically required for intra-abdominal IUDs 4
• Counsel the patient about alternative contraceptive methods 7

Critical Pitfalls to Avoid

• Never assume expulsion without imaging confirmation, as uterine perforation can present with minimal or atypical symptoms that may be misinterpreted 4
• Do not delay investigation if the patient has abdominal pain, even if mild or intermittent 5, 4
• Failure to locate a missing IUD can lead to serious complications including bowel perforation, adhesions, and chronic pain 5

Post-Management Counseling

• Advise the patient to seek immediate care for heavy bleeding, severe cramping, pain, abnormal vaginal discharge, or fever 1, 7
• Discuss alternative contraceptive options if the IUD is removed 7
• Schedule follow-up to ensure symptom resolution and discuss future contraceptive plans 7