What are the possible causes of severe pelvic pain that starts shortly after intrauterine device (IUD) placement?

Severe Pelvic Pain After IUD Insertion: Causes and Evaluation

Severe pelvic pain shortly after IUD placement should immediately raise concern for uterine perforation, IUD malposition (embedded in myometrium or cervix), or failed insertion, all of which require urgent evaluation with ultrasound and potential device removal. 1, 2, 3

Immediate Life-Threatening Causes

Uterine Perforation

• Perforation occurs in 0.12-0.68 per 1,000 insertions and can be life-threatening, presenting with severe pain, bleeding, or may be asymptomatic initially 1
• Can occur during insertion or manifest later, with potential for bowel, kidney, or other visceral injury leading to peritonitis 1, 2
• Suspect perforation when IUD strings are not visible at the external os, though strings may still be visible even with perforation 1, 2
• Requires laparoscopic diagnosis and removal, as the patient is not protected against pregnancy with a perforated device 1

IUD Malposition/Embedment

• Malpositioned IUDs embedded in the myometrium or located in the endocervical canal cause significantly higher rates of severe pain (39.3% vs 19.4%) and bleeding (35.7% vs 15.1%) compared to correctly positioned devices 4
• 16.8% of IUDs may have side arms abnormally located within the myometrium, detectable only on 3D ultrasound coronal view 4
• 75% of patients with malpositioned IUDs present with pain or bleeding, compared to 34.5% with normally positioned devices 4
• Deep myometrial embedment can cause muscularis layer injury to adjacent structures like the recto-sigmoid colon 2
• Removal of malpositioned IUDs results in symptom resolution in 95% of cases (20 of 21 patients) 4

Common Non-Emergent Causes

Expected Post-Insertion Pain

• Most patients experience cramping that peaks during insertion and gradually improves over 5-15 minutes, with intermittent cramping for 24-72 hours being normal 5
• Mild-to-moderate cramping in the first week after insertion is expected and typically responsive to NSAIDs 5

Failed First Insertion Attempt

• Failed insertion is a recognized risk factor for higher pain and should prompt consideration of complications 6, 7

Diagnostic Approach

Clinical Evaluation

• Check for visible IUD strings at the external os—absence suggests perforation or expulsion 1
• Assess pain severity, timing, and associated symptoms (bleeding, fever, vaginal discharge) 2, 3
• Examine for peritoneal signs suggesting visceral injury 1, 2

Imaging

• Ultrasound is the first-line imaging modality, but standard 2D views may miss malposition 4
• 3D ultrasound with coronal view reconstruction is essential to visualize the entire IUD and detect myometrial embedment or cervical positioning 4
• CT can confirm low-lying or malpositioned IUDs but may initially be misinterpreted as normal 3
• Laparoscopy provides definitive diagnosis of perforation and allows for removal 1, 2

Management Algorithm

For Severe Pain (Beyond Expected Post-Insertion Cramping):

1. Perform speculum exam to check for visible strings 1
2. Order ultrasound (preferably 3D with coronal view) immediately 4
3. If perforation or significant malposition detected, arrange for laparoscopic removal 1, 2
4. If IUD is malpositioned but not perforated, remove device—symptoms resolve in 95% of cases 4

For Mild-Moderate Pain (Expected Range):

1. Start scheduled naproxen 500-550 mg orally every 12 hours with food for 24-72 hours 5
2. Apply heating pad to lower abdomen 5
3. Consider acupressure at LI4 and SP6 points bilaterally 5
4. Reassure that cramping typically resolves within 72 hours 5

Critical Pitfalls to Avoid

• Do not assume visible strings mean correct positioning—perforation and malposition can occur with strings still visible 1, 2
• Do not rely solely on 2D ultrasound—malpositioned IUD arms are only detected on 3D coronal views 4
• Do not dismiss severe pain as "normal cramping"—this delays diagnosis of serious complications 2, 3
• Do not perform overtesting for other causes without first confirming correct IUD position on imaging 3
• Patients with malpositioned devices are not protected against pregnancy and require alternative contraception 1