A simple method involving local anaesthesia in the uterus can reduce pain during IUD insertion, according to a new study from the Karolinska Institutet, published in the journal JAMA. The method also increased the proportion of women who found the procedure tolerable. The results may encourage more women to choose an IUD as a method for contraception.
The IUD is an effective and long-acting contraceptive, but fear of pain during insertion make many women choose not to have one inserted. Currently, IUDs are inserted without local anaesthesia or, in some cases, with local anaesthesia administered via an injection into the tissue around the cervix – an injection that could be experienced as painful.
In the new randomised study, researchers investigated whether a small amount of local anaesthetic, introduced into the uterus via a thin plastic catheter a couple of minutes before the procedure, could make the procedure less painful.
The study involved 370 women aged between 18 and 31 who had not previously given birth. The participants were randomly allocated to receive either the local anaesthetic mepivacaine or a saline solution prior to IUD insertion. Neither the participants nor the healthcare staff knew which treatment was being administered.
The results show that pain was reduced in the group receiving active treatment. On a scale from 0 to 100, the average pain score was 43.8 compared with 58.6 in the control group – a reduction of around 15 units. At the same time, the proportion of participants who found the pain tolerable rose from 91.4 to 98.3 per cent.
Photo: Erik Flyg
“We can see that the method not only reduces pain, but also means that more people find the procedure acceptable,” says Helena Kopp Kallner, professor at the Department of Clinical Sciences, Danderyd Hospital, Karolinska Institutet, and senior consultant at the Women’s Clinic at Danderyd Hospital, who is co-last author with Niklas Envall, a postdoctoral researcher at the same department.
The overall experience was also improved. More than half of the women in the treatment group found the procedure easier than expected, compared with around a third in the control group.
An important aspect of the study was that the administration of the anaesthetic itself should also be gentle. The results show that most participants found the administration to be only mildly painful.
“It is a simple method that does not require needles and is easy to use in everyday clinical practice,” says lead author Karin Elgemark, PhD student at the same department.
The researchers point out that the study does not compare the method with other types of pain relief, which is a limitation. This means it is not possible to determine whether the method is more effective than alternative treatments. The results are also based on self-reported pain, which may be influenced by individual experiences.
“Our study shows that the method works when compared with no active treatment, but it also needs to be compared with other pain relief methods,” says Helena Kopp Kallner.
The study was carried out at eleven gynaecological clinics and youth health centres in Sweden. It was funded by the Swedish Research Council. Some of the researchers have reported receiving remuneration for lectures from companies that manufacture intrauterine devices (IUDs), but these organisations played no role in the conduct or analysis of the study.
Publication
“Intrauterine Mepivacaine Instillation vs Placebo for Pain During IUD Placement: A Randomized Clinical Trial” , Karin Elgemark, Niklas Envall, Helena Kopp Kallner, JAMA, online xx 2026, doi: 10.1001/jama.2026.14217
