Can a 6-year-old Mirena (levonorgestrel) IUD user with new-onset bleeding and radiating lower back pain attempt to feel for the IUD strings herself?

Can the Patient Check for IUD Strings?

Yes, the patient should attempt to feel for the IUD strings herself as a first step in evaluating her new-onset symptoms, but she must seek immediate medical evaluation regardless of what she finds, given her concerning presentation of bleeding and radiating lower back pain at 6 years of Mirena use.

Immediate Clinical Context

This patient's symptom constellation—new bleeding plus radiating lower back pain in a 6-year Mirena user—raises serious concerns that require urgent medical assessment, not just string checking 1, 2.

Why String Checking Matters Here

• Missing strings are a red flag for IUD complications: When strings are not visible or palpable, this may indicate IUD displacement, expulsion, or uterine perforation 2, 3.
• The patient can perform an initial self-check: She should attempt to feel for the strings at the cervical os by inserting clean fingers into the vagina 1.
• This is only a screening step, not diagnostic: Whether she feels strings or not, she needs professional evaluation given her symptoms 2.

What the String Check Reveals

If Strings Are Present

• The IUD may still be properly positioned, but her symptoms (bleeding and back pain) could indicate 1, 2:
  • IUD displacement within the uterus
  • Underlying gynecological pathology (polyps, fibroids, infection)
  • Pregnancy (including ectopic)
  • Perforation (even with visible strings)

If Strings Are Missing

• This requires immediate ultrasound evaluation to determine IUD location 2.
• Missing strings may indicate 2, 3:
  • Strings retracted into the cervical canal (benign)
  • IUD expulsion (patient is unprotected)
  • Uterine perforation with migration
  • Pregnancy with IUD displacement

Critical Red Flags in This Case

The combination of new bleeding AND radiating lower back pain is particularly concerning and may suggest 2, 3, 4:

• Uterine perforation: Can present with pain, bleeding, and back pain; perforation incidence is 0.12-0.68 per 1,000 insertions but can occur years after placement 3.
• IUD migration: Rare cases of bladder or bowel perforation present with pain, hematuria, and back pain 4.
• Pelvic infection: Though risk is primarily within 21 days of insertion, new infection can occur 1.
• Ectopic pregnancy: Must be ruled out in any IUD user with new pain and bleeding 1.

Immediate Management Algorithm

1. Patient performs string check at home (if comfortable doing so) 1
2. Seeks urgent medical evaluation within 24-48 hours regardless of findings 2
3. Clinician performs speculum exam to visualize strings 1
4. If strings not visible: Transvaginal ultrasound to confirm IUD location 2
5. If ultrasound cannot locate IUD: Abdominal X-ray to rule out perforation 2
6. Pregnancy test must be performed to rule out pregnancy 1, 2

Common Pitfalls to Avoid

• Do not assume the IUD is properly positioned just because strings are palpable: Perforation and malposition can occur with visible strings 5.
• Do not delay evaluation: At 6 years, this Mirena is near its approved lifespan (typically 5-8 years depending on indication), and complications may increase with prolonged use 1.
• Do not attribute all bleeding to "normal IUD side effects": New-onset bleeding after years of stable use warrants investigation for underlying pathology 1.
• Back pain is not a typical IUD side effect: Radiating lower back pain specifically raises concern for perforation or other serious complications 3, 4.

Bottom Line

While self-checking for strings is reasonable and may provide useful information, this patient's symptom profile demands urgent professional evaluation with imaging regardless of string presence 2, 3. The string check should not delay or replace medical assessment—it should prompt it.