IUD Visualization Over the Pelvis on Lumbar X-Ray: Abnormal Finding Requiring Urgent Evaluation
No, an IUD projecting over the pelvis on a lumbar X-ray is NOT normal and suggests either uterine perforation with intra-abdominal migration or complete expulsion—both scenarios require immediate imaging confirmation and clinical assessment.
Why This Is Abnormal
A properly positioned IUD should be located within the uterine fundus, which sits in the true pelvis below the pelvic brim. When an IUD appears "over the pelvis" on a lumbar spine film (meaning it's visible in the field of view above where the uterus should be), this indicates the device has migrated from its intended intrauterine location 1.
During pregnancy, the uterus grows and rises out of the pelvis, which can make an intrauterine IUD appear higher on imaging 2. However, in a non-pregnant patient, an IUD visible on lumbar imaging suggests:
- Complete uterine perforation with migration into the peritoneal cavity or abdominal wall 3, 1
- Expulsion (though this would typically not be visible on lumbar films)
- Severe displacement from the uterine cavity
Immediate Clinical Actions Required
1. Confirm IUD Location with Appropriate Imaging
- Pelvic ultrasound first: Check if the IUD is in the uterine cavity 4
- If ultrasound shows an empty uterus, obtain an abdominal/pelvic X-ray to locate the device 5, 6
- The combination of uterine sound placement with X-ray has 95% accuracy for diagnosing IUD location 6
2. Assess for Complications
Look specifically for:
- Abdominal or pelvic pain (may indicate perforation or intra-abdominal injury) 3, 5, 7
- Signs of pregnancy (ectopic risk is elevated; perforation can occur during pregnancy) 4
- Infection symptoms (fever, abnormal discharge, peritoneal signs)
- Bowel or bladder symptoms (perforation can involve adjacent organs) 1
3. Surgical Consultation
Complete uterine perforation requires surgical removal 1. An IUD in the peritoneal cavity can cause:
- Adhesions to bowel, omentum, or bladder
- Chronic inflammation
- Potential organ injury
- Continued risk of pregnancy (no contraceptive effect when extrauterine)
Laparoscopic removal is typically indicated and should not be delayed 3, 5.
Common Pitfalls to Avoid
Do not assume expulsion without imaging confirmation 5. The case literature documents patients with years of symptoms attributed to other causes when the IUD was actually intra-abdominal. One patient had a "lost" IUD for 12 years that was eventually found in the anterior abdominal wall 3.
Do not rely solely on ultrasound if strings are not visible and the uterus appears empty 5, 6. A plain abdominal X-ray is inexpensive, non-invasive, and can definitively locate a radiopaque IUD.
Recognize that perforation can occur at insertion or later, including during procedures like dilation and curettage 3. The IUD can migrate over time from the myometrium into the peritoneal cavity 1.
Clinical Context
The incidence of uterine perforation ranges from 1/350 to 1/2,500 insertions 3. When IUD strings are not visible (occurs in 5-25% of cases), the differential includes 6:
- String retraction into the cervical canal
- Expulsion
- Uterine perforation
- Pregnancy with IUD displacement
Malpositioned IUDs in the lower uterine segment or endocervical canal can cause acute pelvic pain and are sometimes misinterpreted as normal on imaging 7. However, an IUD visible on lumbar films is clearly outside the expected anatomic location.
Bottom Line Algorithm
- IUD visible on lumbar X-ray → Obtain pelvic ultrasound immediately
- Empty uterus on ultrasound → Obtain abdominal/pelvic X-ray to locate device
- IUD in peritoneal cavity → Urgent surgical consultation for laparoscopic removal
- IUD in uterus but malpositioned → Gynecology referral for removal/replacement
- Cannot locate IUD → Consider expulsion, but document thoroughly and ensure contraceptive counseling
The key principle: An IUD should always be in the uterine fundus. Any other location is abnormal and requires intervention 1.