What to do when intrauterine device (IUD) strings cannot be visualized with a speculum?

Management of Non-Visible IUD Strings

When IUD strings cannot be visualized with a speculum, immediately perform or refer for transvaginal ultrasound to determine whether the IUD is properly positioned in the uterus, has been expelled, or has perforated the uterine wall. 1

Initial Diagnostic Approach

• Ultrasound is the first-line imaging modality to locate the IUD when strings are not visible 1
• Transvaginal ultrasound should visualize the IUD as centrally located within the endometrial cavity, with the crossbar (if present) in the fundal portion 2
• If ultrasound shows an empty uterine cavity, do not automatically assume expulsion—perforation must be ruled out 3

Critical Pitfall to Avoid

Never assume the IUD was simply expelled if ultrasound shows an empty uterine cavity, especially if the patient has abdominal pain. 3 This is a common error that can lead to delayed diagnosis of uterine perforation with serious consequences.

• If ultrasound does not visualize the IUD in the uterus, obtain a plain abdominal X-ray to locate the device 3, 4
• Abdominal X-ray is relatively cheap, non-invasive, and can easily identify an IUD that has perforated into the abdomen or pelvis 3
• Perforated IUDs have been found in various locations including the peritoneal cavity, fallopian tubes, and embedded in surrounding structures 4, 5

Management Based on IUD Location

If IUD is Properly Positioned in the Uterus

• The device can remain in place if the patient is asymptomatic, even without visible strings 1
• Advise the patient to return promptly for heavy bleeding, cramping, pain, abnormal vaginal discharge, or fever 1

If IUD is Malpositioned (Low-Lying, Extending into Cervix)

• Remove the malpositioned IUD as soon as possible without requiring updated ultrasound if previous imaging confirmed malposition and the patient has persistent symptoms 1, 6
• This is particularly important when the IUD is low-lying, extending into the cervix, or when associated with pelvic pain 1, 6
• The CDC recommends immediate removal in these cases, as there is a high rate of symptom recovery among women who have the IUD removed compared to those who do not 6

If IUD is Embedded in the Myometrium

• Remove an embedded IUD as soon as possible due to increased risks of pain, bleeding, infection, and reduced contraceptive efficacy 7
• Depending on the depth of myometrial penetration, specialized instruments or imaging guidance may be necessary 7
• Do not replace the IUD on the same day—wait at least 4-6 weeks to allow complete healing of the myometrium before considering reinsertion 7

If IUD Has Perforated the Uterus

• An IUD that has perforated the uterus must be removed as soon as possible 1
• This typically requires laparoscopic removal 3
• Delayed diagnosis can lead to chronic abdominal pain and atypical symptoms that may be misinterpreted as psychosocial in origin 3

Advanced Imaging Considerations

• If standard 2D ultrasound fails to visualize the IUD satisfactorily, three-dimensional ultrasound with volume contrast imaging (VCI-C) can visualize acoustic shadows of the IUD, facilitating identification 8, 2
• This technique is particularly useful for difficult cases where the IUD has variable echogenicity or unusual positioning 8

Post-Management Counseling

• Counsel the patient about alternative contraceptive methods if the IUD is removed 1, 7
• Schedule follow-up to ensure symptom resolution and discuss future contraceptive plans 1, 7
• Advise immediate return for heavy bleeding, severe cramping, pain, abnormal vaginal discharge, or fever 1, 6, 7