Objective
Anticipated pain with intrauterine device (IUD) insertion may be a barrier to widespread use. Our objective was to evaluate the efficacy of intracervical 2% lidocaine gel for pain relief with IUD insertion.
Study Design
We performed a double-blind, randomized controlled trial of women undergoing IUD insertion. Participants were randomly assigned to 2% lidocaine or placebo gel. Study gel (3 mL) was placed 3 minutes prior to IUD insertion. Pain scores were measured at various time points using a 10-point visual analog scale.
Results
Of the 200 participants randomized, 199 completed the study. Pain scores among lidocaine and placebo arms were similar at tenaculum placement (lidocaine and placebo: median, 4; range, 0–10; P = .15) and with insertion (lidocaine: median, 5; range, 1–10; placebo: median, 6; range, 0–10; P = .16). These results did not differ by parity.
Conclusion
Topical or intracervical 2% lidocaine gel prior to IUD insertion does not decrease pain scores.
Unintended pregnancy accounts for approximately 50% of pregnancies in the United States with 40% of those ending in induced abortion. Long-acting reversible contraception (LARC), including intrauterine devices (IUDs) and implants, is associated with higher contraceptive effectiveness and lower rates of discontinuation when compared to other reversible methods. IUDs remain an underutilized method of contraception in the United States despite their well-established safety and efficacy. Evidence supports the use of IUDs as a first-line contraceptive option. The low rates of IUD use in the United States may be in part influenced by provider misconception about appropriate candidates. However, there is also concern that some women may not tolerate the pain or discomfort of the IUD insertion procedure. Qualitative studies have identified fear about the insertion procedure as a barrier to IUD use.
Several steps of the IUD insertion have the potential to cause pain or discomfort to the patient: speculum insertion, tenaculum application, manipulation of the cervix, and passage of the uterine sound or IUD through the endocervical canal. Additionally, some studies suggest parity may play an important role in the difficulty of insertion. and the risk for severe pain with insertion. Pain management techniques during IUD insertion have included nonsteroidal anti-inflammatory drugs (NSAIDs), paracervical administration of local anesthetic, and preprocedural administration of misoprostol. Studies are limited and results have been conflicting. Massey et al performed one of the first randomized controlled trials evaluating the effect of naproxen on pain with insertion of the Dalkon Shield (A.H. Robins Company, Richmond, VA). All women received a paracervical block, and all but 1 woman had the IUD inserted at the time of menses. This study failed to find a reduction in pain in the treatment arm with a mean pain score of 2.46 (on a 5-point scale) compared to 2.54 in the control group. More recently Hubacher et al published a large trial of 2019 women randomized to placebo or 400 mg of ibuprofen prior to copper T380A insertion. This study also failed to show a reduction in pain with preinsertion administration of ibuprofen. Overall, NSAIDs have been shown to have some benefit for postprocedure pain, but have not shown improvements in periinsertional pain. Misoprostol has been investigated using different doses and routes of administration. Providers report increased ease of insertion, but have not demonstrated a reduction in pain scores. A recent Cochrane review of interventions for pain with IUD insertion evaluated randomized clinical trials and concluded that there was no benefit to either NSAID use or misoprostol on periinsertional pain. The review also commented on a study published in 1996 in the British Journal of Family Planning that evaluated topical lidocaine as a possible intervention. Despite producing promising results, the study was noted to have methodologic flaws; nonetheless, this study has led to widespread use of topical lidocaine in the United Kingdom. Findings from a recent trial assessing lidocaine gel applied intracervically with cotton-tip application did not find the intervention decreased pain scores.
Lidocaine gel is routinely used in the distal urethra prior to Foley catheter placement, as well as in the nasal canal prior to nasogastric or nasotracheal tube placement. In each of these cases lidocaine gel has been shown to decrease pain scores associated with insertion. The endocervical canal is lined with columnar epithelium as is the nasal canal. The ectocervix and distal urethra share stratified squamous epithelium lending biologic plausibility to this intervention for both tenaculum placement to the ectocervix as well as IUD insertion. The purpose of our study was to evaluate whether intracervical lidocaine gel improved pain scores compared to placebo. We hypothesized that 2% lidocaine gel would reduce the insertional pain.
Materials and Methods
Approval was obtained by the Human Research Protection Office and the Institutional Review Board at Washington University in St. Louis, MO. We performed a single-site, double-blind, randomized controlled trial of women undergoing IUD insertion from Aug. 1, 2011, through Dec. 1, 2011, at Washington University. Women aged 18-45 years presenting to the Contraceptive CHOICE Project were approached for participation. The Contraceptive CHOICE Project is a prospective cohort study of 9256 women designed to promote the use of LARC, remove financial barriers to contraception, and evaluate continuation and satisfaction for reversible methods. We provide each participant with the reversible contraceptive method of her choice at no cost to her.
Additional inclusion criteria for this study were: (1) ability to give written informed consent in English; (2) willingness to be randomized and complete study questionnaires; and (3) no contraindication to or history of allergic reaction to lidocaine. Participants in each of these groups were randomly assigned by random number generator to either 2% lidocaine or water-based lubricant. Randomization was stratified by parity and an equal number of nulliparous (defined as no pregnancy >20 weeks’ gestation) and parous women were enrolled. Participants and the clinician placing the IUD were blinded to allocation.
After informed consent was provided and prior to IUD placement, we gave participants a 10-point visual analog scale (VAS) and asked them to indicate their current pain level and anticipated pain level with insertion. The clinician then performed a bimanual exam, placed the speculum, and cleansed the cervix with topical antiseptic according to usual protocol. The clinician applied 0.5-1 mL of study gel to the ectocervix at the planned tenaculum site. Two to 3 mL of study gel was then inserted via 20G angiocatheter into the endocervical canal. After a 3-minute waiting period, the IUD was inserted in the standard fashion. Participants were asked to rate their pain immediately following tenaculum placement and immediately following device insertion using the same 10-point VAS. All participants received ibuprofen approximately 10 minutes prior to their procedure to minimize postprocedure cramping.
All participants scheduled a follow-up visit for a string check at the time of their insertion. Those who did not complete this follow-up visit were contacted by telephone to assess for any complications related to their insertion. We performed a weekly review of participant telephone calls to the Contraceptive CHOICE Project clinic to evaluate for potential complications (ie, perforation, infection, expulsion) for 6 months following completion of enrollment.
Preliminary data from Contraceptive CHOICE Project of 250 women undergoing IUD insertion found a mean pain score of 4 (SD = 2.5) on a 10-point scale. We considered a 50% reduction in the mean score as a clinically important difference. A total of 43 women per arm were required to reach 90% power with an alpha (type I) error of 0.05. Anticipating the possibility that parity may alter an effect, we planned to stratify by parity and enroll a total 100 nulliparous and 100 parous women, with 50 in each arm. This allowed for a 15% loss in case a woman changed her mind about IUD insertion or there was a failed IUD insertion after randomization.
Using a permuted varying block size randomization scheme with nQuery software (Statistical Solutions Software, Saugus, MA) a predetermined randomization scheme was established. Random assignments were concealed in labeled opaque envelopes until the time of enrollment. The 2 study gels were labeled “A” and “B,” and only 2 study coordinators who were responsible for filling the study gel syringes immediately preceding IUD insertion were aware of the contents of each syringe. Gels were indistinguishable in appearance by color and consistency. Both the participant and the clinician were blinded to the identity of the gel.
Statistical analyses were conducted using SAS 9.2 software (SAS Institute Inc, Cary, NC) and significance was set at P < .05. We performed descriptive analyses comparing the baseline characteristics of participants in each treatment arm. Continuous variables were summarized using means, medians, ranges, and SD. Categorical variables were presented as frequencies. Normally distributed continuous variables were analyzed with Student t test; otherwise, nonparametric testing was used. We used χ 2 and Fisher exact tests to analyze categorical variables. To account for varying levels of baseline (preenrollment pain), tenaculum and insertional pain scores were standardized by subtracting baseline pain levels from the reported procedure pain level. Pain scores were not normally distributed and are therefore presented as median scores. These scores were analyzed both in the entire cohort as well as in parity subgroups using the Wilcoxon rank sum test.
The trial was registered with clinicaltrials.gov under protocol record 201105067.
Results
We enrolled and randomized a total of 200 women from August through December 2011. Of the 202 women approached for participation, 2 did not meet inclusion criteria. There were no women approached who declined participation. There was 1 failed insertion in the nulliparous group leaving 199 women for analysis ( Figure ). There were no differences in demographic characteristics between the 2 groups ( Table 1 ). Of participants, 76% in each arm chose the levonorgestrel intrauterine system; a rate similar to the overall rates found in the Contraceptive CHOICE Project. The majority of IUDs were inserted by a single physician or single experienced nurse practitioner. A small number (7.5%) were inserted by resident physicians. The proportion of insertions by each of these entities was similar in both intervention arms.
| Characteristic | Placebo (n = 99) | Lidocaine (n = 100) | ||
|---|---|---|---|---|
| n | % | n | % | |
| Age, y | ||||
| 18-20 | 10 | 10.1 | 19 | 19.0 |
| 21-25 | 36 | 36.4 | 30 | 30.0 |
| 26-45 | 53 | 53.5 | 51 | 51.0 |
| Race | ||||
| Black | 38 | 38.4 | 37 | 37.0 |
| White | 51 | 51.5 | 54 | 54.0 |
| Other | 10 | 10.1 | 9 | 9.0 |
| BMI | ||||
| ≤18.5 | 2 | 2.0 | 3 | 3.0 |
| >18.5-25 | 41 | 41.4 | 45 | 45.0 |
| >25-30 | 28 | 28.3 | 28 | 28.0 |
| ≥30 | 28 | 28.3 | 24 | 24.0 |
| Parity | ||||
| 0 | 50 | 50.5 | 50 | 50.0 |
| 1-2 | 38 | 38.4 | 42 | 42.0 |
| ≥3 | 11 | 11.1 | 8 | 8.0 |
| Education | ||||
| ≤High-school | 18 | 18.2 | 15 | 15.0 |
| Some college | 40 | 40.4 | 52 | 52.0 |
| College graduate | 41 | 41.4 | 33 | 33.0 |
| Income (monthly) | ||||
| None | 15 | 15.2 | 19 | 19.0 |
| $1-800 | 21 | 21.2 | 30 | 30.0 |
| $801-1600 | 29 | 29.3 | 27 | 27.0 |
| >$1600 | 33 | 33.3 | 24 | 24.0 |
| History of abortion | ||||
| No | 73 | 73.7 | 75 | 75.0 |
| Yes | 26 | 26.3 | 25 | 25.0 |
| History of STI a | ||||
| No | 67 | 67.7 | 59 | 59.0 |
| Yes | 32 | 32.3 | 41 | 41.0 |
| IUD type | ||||
| LNG | 75 | 75.8 | 77 | 77.0 |
| Copper | 24 | 24.2 | 23 | 23.0 |
| Clinician inserter | ||||
| Physician | 44 | 44.4 | 46 | 46.0 |
| Nurse practitioner | 45 | 45.5 | 48 | 48.0 |
| Resident | 9 | 9.1 | 6 | 6.0 |
| Baseline pain score b | ||||
| 0 | 91 | 91.9 | 90 | 90.0 |
| 1 | 4 | 4.0 | 5 | 5.0 |
| 2 | 2 | 2.0 | 3 | 3.0 |
| 3 | 1 | 1.0 | 1 | 1.0 |
| 4 | 1 | 1.0 | 1 | 1.0 |
a Gonorrhea, chlamydia, trichomoniasis, human papilloma virus, herpes simplex virus
Insertional pain scores reported between nulliparous and parous women were significantly different regardless of intervention ( Table 2 ). The median pain score reported in the placebo group was 7 (range, 2–10) among nulliparous women and 5 (range, 0–9) among parous women ( P < .01). The median pain score reported in the lidocaine group was 6 (range, 2–10) by nulliparous women and 4 (range, 1–10) by parous women ( P = .01).
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