Cervical Block Procedure for IUD Insertion
For optimal pain management during IUD insertion, an intracervical block (ICB) is recommended as an effective technique, using 4 mL of 2% lidocaine injected at the 3,6,9, and 12 o'clock positions of the cervix with a 27-gauge needle prior to tenaculum placement. 1
Types of Cervical Blocks for IUD Insertion
Intracervical Block (ICB)
- Use a 27-gauge needle to inject 4 mL of 2% lidocaine intracervically at the 3,6,9, and 12 o'clock positions before tenaculum placement 1
- If 2% lidocaine is unavailable, 1% lidocaine with a standard syringe can be used as an alternative 1
- No waiting period is required after ICB injection as it does not appear to significantly reduce pain effectiveness 1
- ICB has demonstrated reduced pain with both tenaculum placement and IUD insertion, particularly in nulliparous patients 1
- ICB with 6 mL of 2% lidocaine has been shown to be more effective than naproxen 550 mg alone in reducing pain during levonorgestrel IUD insertion 1
Paracervical Block (PCB)
- Start with a superficial intracervical injection of 2 mL of buffered 1% lidocaine at the tenaculum site (typically anterior lip of cervix) 1
- After placing the tenaculum, inject the remaining anesthetic at the 4 o'clock and 8 o'clock positions at the cervicovaginal junction using a 22- or 25-gauge 1.5" needle 1
- Create a small wheal at the junction and inject slowly while moving the needle 1
- Always aspirate for blood prior to injection to avoid intravascular administration 1
- Consider buffering the lidocaine by combining 2 mL of sodium bicarbonate with 18 mL of 1% lidocaine for a 20 mL block to decrease burning sensation during injection 1
Evidence-Based Recommendations
Medication Selection
- 2% lidocaine is preferred for ICB based on clinical evidence 1
- If using PCB, buffered 1% lidocaine (mixing 2 mL sodium bicarbonate with 18 mL of 1% lidocaine) can reduce injection pain 1
- Research shows that 2% lidocaine gel applied topically is not effective for pain reduction during IUD insertion 2
- EMLA cream (lidocaine-prilocaine) applied to the cervix has shown effectiveness in some studies 1, 3
Procedure Timing
- No waiting period is required after ICB/PCB injection before proceeding with IUD insertion 1
- Warn patients about potential self-limiting side effects of intravascular lidocaine, such as numbness of the tongue or tinnitus 1
Special Considerations
- PCB is particularly helpful for more challenging IUD placements, such as those requiring cervical dilation 1
- For failed first attempts at IUD placement, consider misoprostol 400 mcg buccally or vaginally 3-4 hours before placement or 200 mcg 10 and 4 hours before placement in addition to ICB/PCB 1
- In nulliparous patients, ICB has demonstrated improved patient experience and reduced pain scores 1
Post-Procedure Care
- After successful placement, have the patient lie supine on the examination table with legs out of footrests for 5 minutes 1
- Gradually raise the head of the table to reduce risk of vasovagal episodes 1
- Offer a drink, snack, and/or heating pad for the lower abdomen 1
- Advise the patient to take an NSAID with food on a scheduled basis for the first 24-72 hours postprocedure 1
Common Pitfalls and Caveats
- Always aspirate before injection to avoid intravascular administration of lidocaine 1
- Monitor for signs of lidocaine toxicity (circumoral numbness, facial tingling, slurred speech, metallic taste) 4
- Topical 2% lidocaine gel has not shown effectiveness in reducing IUD insertion pain in clinical trials 2
- Misoprostol should be used cautiously and only in cases of failed placement or selected patients with risk factors for failed insertion, as it can increase post-procedure cramping 1, 5
By following this evidence-based approach to cervical block for IUD insertion, providers can significantly reduce patient discomfort and improve the overall experience, potentially increasing acceptance and utilization of this highly effective contraceptive method.