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

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 group