Management of Non-Visible IUD Strings with Confirmed Proper Positioning
If ultrasound confirms the IUD is properly positioned and the patient is asymptomatic, leave the device in place. 1
Clinical Algorithm
When Strings Are Not Visible
First step: Obtain ultrasound to determine IUD location, as the device may still be in the uterus, may have been expelled, or may have perforated the uterine wall 1
If ultrasound confirms proper intrauterine position AND patient is asymptomatic: The IUD can remain in place without intervention 1
If ultrasound shows an empty uterine cavity: Do not assume expulsion alone—obtain an abdominal X-ray to rule out uterine perforation, as this is relatively cheap, non-invasive, and can detect an IUD that has migrated into the peritoneal cavity 2
Patient Counseling and Follow-Up
Advise the patient to return promptly if she develops heavy bleeding, cramping, pain, abnormal vaginal discharge, or fever 1
Inform the patient that the IUD remains effective for contraception even without visible strings 1
Explain that future removal may require ultrasound guidance or hysteroscopy if strings remain non-visible 3
Important Clinical Caveats
String Visibility Varies by Insertion Type
String visibility is significantly lower after cesarean section insertion (72.4%) compared to vaginal insertion (98.1%) at 1 year follow-up 4
Non-visible strings occur in approximately 21% of postplacental insertions at 1 year, with the IUD remaining properly positioned 4
When to Remove Despite Proper Position
Remove the IUD if it is malpositioned: low-lying, extending into the cervix, or embedded in the myometrium, especially when associated with pelvic pain 1
Remove immediately if perforation is confirmed: An IUD that has perforated the uterus must be removed as soon as possible, typically requiring laparoscopy 1, 2
Remove if the patient develops symptoms: persistent pelvic pain, abnormal bleeding, or signs of infection warrant removal even if initially well-positioned 3, 1
Pitfall to Avoid
Do not assume expulsion when ultrasound shows an empty cavity—this case presentation demonstrates that failure to obtain an abdominal X-ray can result in years of undiagnosed perforation with the IUD in the peritoneal cavity 2
The accuracy of ultrasound in identifying IUDs varies by device type, with copper devices more reliably visualized than older devices like the Lippes Loop 5