What is the best course of action for a reproductive-aged woman with a 6-year-old Mirena (levonorgestrel-releasing intrauterine device) IUD in place, presenting with new-onset bleeding and radiating lower back pain?

Management of 6-Year-Old Mirena IUD with New-Onset Bleeding and Radiating Lower Back Pain

This patient requires immediate evaluation for IUD displacement, uterine perforation, pregnancy, pelvic inflammatory disease, and new pathologic uterine conditions, as new-onset heavy or prolonged bleeding in a long-term IUD user (especially at 6 years when the device is at its FDA-approved lifespan limit) is uncommon and warrants investigation before attributing symptoms to the device alone. 1

Immediate Clinical Assessment Required

Critical Differential Diagnoses to Exclude

Heavy or prolonged bleeding is uncommon during LNG-IUD use, particularly after years of stable use, making new-onset bleeding at 6 years a red flag for underlying pathology. 1

When clinically indicated (which this presentation clearly is), you must systematically evaluate for:

• IUD displacement or expulsion: Check for visible strings on speculum exam; if strings are not visualized or appear longer/shorter than baseline, obtain transvaginal ultrasound to confirm intrauterine position 1
• Uterine perforation: The combination of new bleeding and radiating lower back pain raises concern for perforation, which can be life-threatening and require emergent surgical intervention 2
• Pregnancy (intrauterine or ectopic): Rule out pregnancy immediately, as the Pearl Index increases in year 6-8 of use (0.34 per 100 woman-years in year 6) and ectopic pregnancy risk exists 3
• Sexually transmitted infection or pelvic inflammatory disease: Obtain cervical cultures for gonorrhea and chlamydia 1
• New pathologic uterine conditions: Evaluate for polyps, fibroids, endometrial hyperplasia, or malignancy, particularly given the 6-year duration of use 1

Specific Diagnostic Workup

• Pelvic examination: Assess for cervical motion tenderness, adnexal masses, uterine size/tenderness, and IUD string visualization 1
• Urine or serum pregnancy test: Mandatory first step 1
• Transvaginal ultrasound: Essential to confirm IUD position and evaluate for structural abnormalities 2
• STI screening: Cervical swabs for gonorrhea/chlamydia 1
• Consider endometrial sampling: If IUD is properly positioned and other causes excluded, particularly given 6-year duration approaching device lifespan 1

Device Lifespan Considerations

The Mirena IUD is FDA-approved for 5 years, though recent evidence supports efficacy through 8 years; however, this patient is at 6 years with new symptoms, making device replacement a reasonable consideration after excluding other pathology. 3

• The 52-mg levonorgestrel IUD maintains contraceptive efficacy through 8 years with a 3-year Pearl Index of 0.28 for years 6-8 3
• Levonorgestrel release decreases over time (from 40-50 mcg/day at 1 year to 25-30 mcg/day at 5 years), which may contribute to changing bleeding patterns 4
• Approximately half of users experience amenorrhea or infrequent bleeding by year 2, so new bleeding at year 6 represents a significant pattern change requiring investigation 1

Management Algorithm

If Serious Pathology is Identified

• IUD displacement/perforation: Remove device if displaced; if perforation confirmed, surgical consultation required 2
• Pregnancy: Remove IUD if intrauterine pregnancy confirmed (after antibiotics started to reduce bacterial spread risk); ectopic pregnancy requires appropriate medical or surgical management 1, 3
• PID: Treat according to CDC STD Treatment Guidelines; IUD does not need immediate removal if patient desires continued contraception, but reassess in 24-48 hours and remove if no clinical improvement 1
• Uterine pathology: Treat condition or refer for specialized care 1

If No Underlying Pathology Found

If evaluation excludes serious causes and the IUD is properly positioned, initiate symptomatic treatment with scheduled NSAIDs while counseling about device replacement options. 1

• First-line treatment: Naproxen 500-550 mg orally every 12 hours with food for 24-72 hours 5, 6
• Alternative NSAID: Ibuprofen 600-800 mg every 6-8 hours with food if naproxen contraindicated 5, 6
• Adjunctive measures: Heating pad to lower abdomen/back, bilateral acupressure at LI4 and SP6 points 5, 6

Device Replacement Decision

Given the 6-year duration (beyond FDA-approved 5 years, though within evidence-supported 8-year window) and new symptomatic bleeding:

• Counsel patient on device replacement: Offer removal and replacement with new IUD if continued contraception desired 1
• Alternative contraceptive counseling: If bleeding persists and patient finds it unacceptable despite treatment, discuss alternative methods 1
• Continuation option: If symptoms resolve with treatment and patient satisfied, continuation through year 8 is supported by evidence showing maintained efficacy and favorable bleeding patterns in women who elect to continue 3

Critical Pitfalls to Avoid

• Do not attribute new bleeding to "normal IUD side effects" without thorough evaluation: Heavy or prolonged bleeding is uncommon with LNG-IUD, especially after years of stable use 1
• Do not miss uterine perforation: Radiating lower back pain combined with bleeding warrants imaging to exclude this potentially life-threatening complication 2
• Do not delay pregnancy testing: Even with proper IUD use, pregnancy can occur (particularly in years 6-8) and ectopic pregnancy risk exists 3
• Do not remove IUD immediately if PID suspected: Start antibiotics first to reduce bacterial spread risk from removal procedure 1