Mepivacaine instillation for pain reduction during intrauterine device placement in nulliparous women: a double-blinded randomized trial - 21/06/24

Doi : 10.1016/j.ajog.2024.05.038

Niklas Envall, RNM, PhD ^a,^b,^c, Karin Elgemark, MD ^a,^d,^⁎ , Helena Kopp Kallner, MD, PhD ^a,^c,^d
^a Department of Clinical Sciences, Danderyd Hospital, Karolinska Institutet, Stockholm, Sweden
^b School of Health and Welfare, Dalarna University, Falun, Sweden
^c Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
^d Department of Obstetrics and Gynecology, Danderyd Hospital, Stockholm, Sweden

^∗Corresponding author: Karin Elgemark, MD.

Sous presse. Épreuves corrigées par l'auteur. Disponible en ligne depuis le Friday 21 June 2024

Abstract

Background

Fear of pain associated with intrauterine device (IUD) placement has been identified as a significant barrier to the adoption of long-acting reversible contraception, contributing to lower utilization of the most effective reversible contraceptive methods.

Objective

To assess whether instillation of intrauterine mepivacaine before IUD placement alleviates pain more effectively than a placebo.

Study design

We conducted a multicenter, double-blind, randomized, placebo-controlled trial involving nulliparous women undergoing IUD placement. An intrauterine instillation of 10 mL of 20 mg/mL mepivacaine or 0.9 mg/mL sodium chloride was administrated through a hydrosonography catheter 2 minutes prior to IUD placement. Pain scores were assessed using a 100 mm visual analog scale (VAS) at prespecified time points. Primary outcome measured the difference in VAS pain scores between the intervention group and the placebo group during IUD placement. Secondary outcomes included VAS pain scores at instillation and 10 minutes after placement, tolerability of the placement pain, as well as acceptability of the analgesia method.

Results

We enrolled 151 participants, with 76 assigned to the mepivacaine group and 75 to the placebo group. The mean VAS pain score during IUD placement showed a difference of 13.3 mm (95% confidence interval (CI) 5.75–20.87; P<.001): the mepivacaine group had a mean of 53.9 mm (standard deviation [SD] 22.8), while the placebo group had a mean of 67.2 mm (SD 22.4). After adjusting for each individual provider's impact, the difference in mean pain scores remained statistically significant (12.2 mm 95% CI 4.85–19.62; P<.001). A greater proportion of women in the intervention group reported tolerable pain during placement with 70/75 participants (93.3%) compared to 53/66 participants (80.3%) in the placebo group (P=.021).

Conclusion

The intrauterine instillation of mepivacaine results in statistically significant reduction in pain score among nulliparous women during IUD placement. Although the precise clinical impact of this pain reduction method remains uncertain, the observed reduction in pain score result in a higher proportion of women reporting tolerable pain. This finding and the high acceptance as a pain reduction method thereby suggests clinical relevance. Intrauterine instillation of mepivacaine is a possible strategy to increase IUD utilization, particularly among nulliparous women who are at high risk of unintended pregnancy.

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Key words : analgesia, contraception, family planning services, hormone-releasing intrauterine device, intrauterine devices, long-acting reversible contraception, mepivacaine, pain, topical anesthetic, visual analog scale

Plan

Results in context of what is known

Clinical implications

Research implications

Strengths and limitations

Conclusion

	Clinical trials registration
	Date of registration: 2021 March 04.
	Date of initial participant enrollment: 2021 May 17.
	Clinical trial identification number: Eudra CT no: 2020-002271-36.
	URL of the registration site: index.html.
	N.E. has received personal fees from Bayer for educational activities and honorarium from Medsphere Corp USA for expert opinions on long-acting reversible contraception, outside the submitted work. H.K.K. has received honoraria for consultancy work and lectures from Abbvie, Actavis, Bayer, Exeltis, Gedeon Richter, Natural Cycles, Nordic Pharma, Merck, Mithra, Teva, Organon, Ferring, Consilient Health and providing expert opinion for Bayer, Evolan, Gedeon Richter, Exeltis, Merck, Teva, TV4 och Natural Cycles, Dynamic Code, Ellen, Estercare, Pharmiva, Gedea, Gesynta, Essity, and Preglife; is an investigator in trials sponsored by Bayer, MSD, Mithra, Ethicon, Azanta/Norgine, Gedeon Richter, Gedea, planned study for Organon, Pharmiva, and Takeda. None of the above mentioned entities have had any influence on study design, interpretation of results, or manuscript writing. K.E. reports no conflict of interest.
	The study was financed by the The Swedish Research Council, grant # 2020-00653. The funding sources were not involved in study design, in the collection, analysis or interpretation of data, in the writing of the report, or in the decision to submit the article for publication.
	Data sharing: The full pseudonymized dataset as well as study protocol will be made available upon request from the corresponding author and be shared with the requester in.sav format (for use in SPSS) from date of submission until 2029 December 31.
	Preliminary results presented at Reproductive Health Conference 2023, The Swedish Association of Midwives, Karlstad, Sweden, Oct. 3–4, 2023.
	Cite this article as: Envall N, Elgemark K, Kopp Kallner H. Mepivacaine instillation for pain reduction during intrauterine device placement in nulliparous women: a double-blinded randomized trial. Am J Obstet Gynecol 2024;XXX:XX–XX.