Difficult IUD Insertion

Difficult insertion means that the cervix cannot be passed, the sound or inserter meets resistance, the uterine cavity is unusual in size or position, or the patient's pain or reaction prevents completion. It occurs most often in nulliparous patients, after cervical surgery, in postmenopausal or breastfeeding patients, and in patients with a retroverted or acutely anteflexed uterus. The aim is to complete the insertion safely or stop without harm.

Common causes.

• Cervical stenosis (nulliparity, previous cone biopsy or cautery, postmenopausal state, long-term progestogen use).

• Uterine anomaly, fibroids or a retroverted or acutely anteflexed uterus.

• Patient pain, anxiety or vasovagal reaction.

• Inadequate traction or poor visualisation.

• Insertion soon after delivery or during breastfeeding, when the uterus is soft.

Preparation.

• Take a careful history, perform a bimanual examination and use ultrasound if the uterine position is unclear.

• Give ibuprofen 400 to 800 mg 30 to 60 minutes before and use local anaesthetic (lidocaine 1% paracervical block) for patients who are anxious, nulliparous or have had a difficult previous insertion.

• Choose a smaller device or inserter for nulliparous patients.

• Ensure an experienced provider is available.

Stopping rules. Stop if the sound will not pass, if the uterus sounds under 6 cm or over 9 cm, if pain is severe, or if perforation is suspected.

Step by step approach.

• Reassess uterine position by bimanual examination; adjust the tenaculum traction to straighten the canal.

• Use a thinner device or inserter if available.

• Cervical stenosis: apply paracervical block (lidocaine 1% 10 mL in total, divided between 4 and 8 o'clock, giving a maximum of 4.5 mg/kg of lidocaine), wait 2 to 3 minutes, then dilate gently with graduated dilators to the smallest size that allows the inserter to pass; do not use force.

• Use ultrasound to show the position of the sound or inserter when the cavity cannot be negotiated.

• Misoprostol 400 micrograms vaginally or sublingually 3 to 4 hours before insertion may be considered when stenosis is known; it is not used routinely and causes cramping and diarrhoea.

• Limit attempts: no more than two attempts at one visit.

• If the insertion cannot be completed, stop, give an interim method and arrange a repeat attempt by an experienced provider with ultrasound, or at a time when the cervix is softer, such as during menses.

Suspected uterine perforation.

• Stop at once and remove the device and instruments if it is safe to do so.

• Keep the patient lying at rest, start an intravenous line and monitor pulse, blood pressure and abdominal tenderness, guarding and rigidity for several hours.

• Give a prophylactic antibiotic, for example amoxicillin 500 mg orally three times daily with metronidazole 400 mg orally three times daily for 5 to 7 days.

• Refer urgently for emergency surgical assessment if there is severe abdominal pain, change in vital signs or peritoneal signs.

Problems and responses.

• Vasovagal reaction: stop, lay flat with legs raised, give oxygen, monitor.

• Cervical laceration or bleeding: apply pressure; repair if large.

• Device partly inserted or left in the cervical canal: remove it and reinsert a new device or defer.

• Contaminated device: discard and use a new one.

• Perforation with the device in the pelvis or abdomen: refer for imaging and laparoscopic or open removal.

• Persistent pain after the procedure: assess for infection, perforation or malposition.

Lidocaine toxicity. Signs are perioral numbness, metallic taste, tinnitus, agitation, seizures and arrhythmia. Stop the injection, give oxygen, treat seizures with diazepam 5 to 10 mg intravenously, and give lipid emulsion 20% 1.5 mL/kg intravenously as a bolus in severe toxicity.

After a successful difficult insertion. Rest, observe for pain and bleeding, and give clear return instructions for fever, severe pain, heavy bleeding or missing strings. Review at 3 to 6 weeks and consider an ultrasound to confirm the position.

After a failed insertion. Provide an interim method (condoms, pills, injectable or implant), plan a repeat insertion with a more experienced provider, and document what was found and tried.

After suspected perforation. Observe in a facility until stable, provide antibiotics, give return instructions and arrange early review and imaging. Provide a nonhormonal or hormonal interim method.

Special groups. Nulliparous patients and breastfeeding patients have the highest risk of difficulty and perforation. Postmenopausal patients rarely need IUD insertion.

Referral and escalation. Refer for repeat attempts under ultrasound, for suspected perforation, for abnormal cavity or uterine anomaly, and for any patient in whom insertion has failed twice.