Intracervical block for levonorgestrel-releasing intrauterine system placement among nulligravid women: a randomized double-blind controlled trial

Abstract

Fear of pain during the insertion of intrauterine contraceptives is a barrier to using these methods, especially for nulligravidas. An intracervical block may be easier and more reproducible than a paracervical block; however, this intervention has not been evaluated in nulligravid women to reduce pain with intrauterine contraceptive insertion. To evaluate whether a 3.6-mL 2% lidocaine intracervical block reduces pain at tenaculum placement and levonorgestrel-releasing intrauterine system insertion among nulligravidas; and, in addition, to assess whether the intracervical block has any effect on the ease of device insertion and on the overall experience with the procedure. In this randomized double-blind controlled trial, nulligravidas were block-randomized to 1 of 3 arms prior to 52-mg levonorgestrel-releasing intrauterine system insertion: 3.6-mL 2%-lidocaine intracervical block, sham injection (intracervical dry-needling), or no intervention. The primary outcome was pain at levonorgestrel-releasing intrauterine system insertion. Secondary outcomes were pain at tenaculum placement, ease of insertion (assessed by healthcare providers), and the overall experience with the procedure (pain with levonorgestrel-releasing intrauterine system insertion compared with expectations, discomfort level, wish to undergo another device insertion in the future, and recommendation of the procedure to others). Participants' pain was measured with a 10-cm visual analogue scale and a 5-point Faces Pain Scale. Pain was summarized into categories (none, mild, moderate, severe) and also analyzed as a continuous variable (mean and 95% confidence interval). Our sample size had 80% power (α= 0.05) to detect a 15% difference in pain score measured by visual analogue scale (mean [standard deviation] visual analogue scale score= 5.9 [2.0] cm) and an absolute difference of 20% in the proportion of women reporting severe pain at levonorgestrel-releasing intrauterine system insertion among groups. We used a χ2 test and a mixed-effects linear regression model. We calculated the number needed to treat for the intracervical block to avert severe pain at tenaculum placement and levonorgestrel-releasing intrauterine system insertion. A total of 302 women were randomized (99 to the intracervical block, 101 to the intracervical sham, and 102 to no intervention), and 300 had a successful device insertion. The intracervical block group had fewer women reporting severe pain than the other groups, both at tenaculum placement (intracervical block: 2% vs sham: 30.2% vs no intervention: 15.2%, P < .0001) and at levonorgestrel-releasing intrauterine system insertion (intracervical block: 26.5% vs sham: 59.4% vs no intervention: 50.5%, P < .0001). The mean (95% confidence interval) pain score reported at levonorgestrel-releasing intrauterine system insertion was lower in the intracervical block group than in the other groups (intracervical block: 4.3 [3.8-4.9] vs sham: 6.6 [6.2-7.0], P < .0001; intracervical block: 4.3 [3.8-4.9] vs no intervention: 5.8 [5.3-6.4], P < .0001). Women from the intracervical block group reported less pain than expected (P < .0001), rated the insertion as less uncomfortable (P < .0001), and were more willing to undergo another device insertion in the future (P < .01) than women in the other groups. The ease of insertion were similar among groups. The number needed to treat for the intracervical block to avert severe pain at tenaculum placement and levonorgestrel-releasing intrauterine system insertion was 2 and 4, respectively. A 3.6-mL 2% lidocaine intracervical block decreased pain at tenaculum placement and levonorgestrel-releasing intrauterine system insertion among nulligravidas. It also provided a better overall experience during the procedure.