Uterine cervix anesthesia for placement of levonorgestrel-releasing IUD

Posted January 12, 2020

Fear of pain may be one of the factors that contribute for many women, especially those who have never become pregnant, to decide not to use an intrauterine device (IUD).

According to the researcher and professor at INCT Hormona, Dr. Carolina Sales Vieira Macedo, these devices are highly effective and safe methods, but they are used by less than 2% of Brazilian women. There are several types of IUD: copper IUD – many models – and hormonal IUD – two models: conventionally sized one with a smaller one. “They have few side effects and can be used by most women, including teenagers and women who have never become pregnant,” the specialist explains.

It is known that nulligravid women present with more pain during the insertion of any IUD. This was the topic of a study supported by INCT Hormona that was internationally awarded as one of four best papers in 2019 by the Society of Family Planning (SFP), during the last congress held in Los Angeles. The study was also published in American Journal of Obstetrics and Gynecology, one the best and most renowned journals on gynecology and obstetrics worldwide.

The paper assessed whether intracervical block with 3.6 mL 2% lidocaine, i.e., uterine cervix anesthesia, could reduce pain associated with the insertion of a conventionally sized hormonal IUD. This type of IUD is technically named levonorgestrel-releasing intrauterine system. Furthermore, the study entitled Intracervical block for levonorgestrel-releasing intrauterine system placement among nulligravid women: a randomized double-blind controlled trial” analyzed whether intracervical block had some effect on ease of device insertion by the physician and on women’s overall experience with the procedure.

A total of 302 women participated in the study, of which 300 had a successful device insertion, and were divided into three groups. Participants were randomly assigned as follows:

  • 99 to the intracervical block group: each woman received 3.6 mL anesthesia (2% lidocaine) to the uterine cervix. The syringe used was the same as that used by dentists to apply anesthesia. The advantage of this syringe is the fact that its needle is very thin.
  • 101 to the group that received sham anesthesia: Anesthesia was not injected, and participants received only a sham injection.
  • 102 to the control group: they did not receive intervention. This is the usual procedure for IUD placement, with no anesthesia.

The professional who conducted the procedure were blind to the group to which participants were assigned.

According to the researcher, women in the intracervical block group had few reports of severe pain at levonorgestrel-releasing intrauterine system insertion compared to the other two groups. “Women in the intracervical block group reported less pain than expected, rated the insertion as less uncomfortable than expected, and were more willing to undergo another IUD insertion in the future than women in the other groups,” the specialist remarks.

After data analysis, the group of researchers concluded that intracervical block with 3.6 mL 2% lidocaine decreased pain at levonorgestrel-releasing intrauterine system placement among nulligravidas. The procedure also provided a better overall experience during IUD insertion.

The complete Abstract can be accessed at: https://pubmed.ncbi.nlm.nih.gov/31541635/