PAIN control for intrauterine device insertion: a randomized trial of 1% lidocaine paracervical block

Interventions for pain with intrauterine device insertion

BACKGROUND

Fear of pain during insertion of intrauterine contraception (IUC) is a barrier to use of this method. IUC includes copper-containing intrauterine devices and levonorgestrel-releasing intrauterine systems. Interventions for pain control during IUC insertion include non-steroidal anti-inflammatory drugs (NSAIDs), local cervical anesthetics, and cervical ripening agents such as misoprostol.

OBJECTIVES

To review randomized controlled trials (RCTs) of interventions for reducing IUC insertion-related pain

SEARCH METHODS

We searched for trials in CENTRAL, MEDLINE, EMBASE, POPLINE, ClinicalTrials.gov, and ICTRP. The most recent search was 22 June 2015. We examined reference lists of pertinent articles. For the initial review, we wrote to investigators to find other published or unpublished trials.

SELECTION CRITERIA

We included RCTs that evaluated an intervention for preventing IUC insertion-related pain. The comparison could have been a placebo, no intervention, or another active intervention. The primary outcomes were self-reported pain at tenaculum placement, during IUC insertion, and after IUC insertion (up to six hours).

DATA COLLECTION AND ANALYSIS

Two authors extracted data from eligible trials. For dichotomous variables, we calculated the Mantel-Haenszel odds ratio (OR) with 95% confidence interval (CI). For continuous variables, we computed the mean difference (MD) with 95% CI. In meta-analysis of trials with different measurement scales, we used the standardized mean difference (SMD).

MAIN RESULTS

We included 33 trials with 5710 participants total; 29 were published from 2010 to 2015. Studies examined lidocaine, misoprostol, NSAIDs, and other interventions. Here we synthesize results from trials with sufficient outcome data and moderate- or high-quality evidence.For lidocaine, meta-analysis showed topical 2% gel had no effect on pain at tenaculum placement (two trials) or on pain during IUC insertion (three trials). Other formulations were effective compared with placebo in individual trials. Mean score for IUC-insertion pain was lower with lidocaine and prilocaine cream (MD -1.96, 95% CI -3.00 to -0.92). Among nulliparous women, topical 4% formulation showed lower scores for IUC-insertion pain assessed within 10 minutes (MD -15.90, 95% CI -22.77 to -9.03) and at 30 minutes later (MD -11.10, 95% CI -19.05 to -3.15). Among parous women, IUC-insertion pain was lower with 10% spray (median 1.00 versus 3.00). Compared with no intervention, pain at tenaculum placement was lower with 1% paracervical block (median 12 versus 28).For misoprostol, meta-analysis showed a higher mean score for IUC insertion compared with placebo (SMD 0.27, 95% CI 0.07 to 0.46; four studies). In meta-analysis, cramping was more likely with misoprostol (OR 2.64, 95% CI 1.46 to 4.76; four studies). A trial with nulliparous women found a higher score for IUC-insertion pain with misoprostol (median 46 versus 34). Pain before leaving the clinic was higher for misoprostol in two trials with nulliparous women (MD 7.60, 95% CI 6.48 to 8.72; medians 35.5 versus 20.5). In one trial with nulliparous women, moderate or severe pain at IUC insertion was less likely with misoprostol (OR 0.30, 95% CI 0.16 to 0.55). In the same trial, the misoprostol group was more likely to rate the experience favorably. Within two trials of misoprostol plus diclofenac, shivering, headache, or abdominal pain were more likely with misoprostol. Participants had no vaginal delivery. One trial showed the misoprostol group less likely to choose or recommend the treatment.Among multiparous women, mean score for IUC-insertion pain was lower for tramadol 50 mg versus naproxen 550 mg (MD -0.63, 95% CI -0.94 to -0.32) and for naproxen versus placebo (MD -1.94, 95% CI -2.35 to -1.53). The naproxen group was less likely than the placebo group to report the insertion experience as unpleasant and not want the medication in the future. An older trial showed repeated doses of naproxen 300 mg led to lower pain scores at one hour (MD -1.04, 95% CI -1.67 to -0.41) and two hours (MD -0.98, 95% CI -1.64 to -0.32) after insertion. Most women were nulliparous and also had lidocaine paracervical block.

AUTHORS' CONCLUSIONS

Nearly all trials used modern IUC. Most effectiveness evidence was of moderate quality, having come from single trials. Lidocaine 2% gel, misoprostol, and most NSAIDs did not help reduce pain. Some lidocaine formulations, tramadol, and naproxen had some effect on reducing IUC insertion-related pain in specific groups. The ineffective interventions do not need further research.