Effect of uterine sound on pain perception during intrauterine device insertion: A randomized trial.

BACKGROUND

This study aimed to compare the pain scores between patients who underwent intrauterine device (IUD) insertion with uterine sounds and those who underwent the procedure without uterine sounds. We also investigated factors associated with pain during IUD insertion.

METHODS

This randomized, controlled, single-blind clinical trial (ClinicalTrials.gov: NCT05956184; date of registration July 13, 2023) included 128 participants who received IUDs for contraception. They were randomly assigned to 2 groups: IUD insertion with or without the use of uterine sounds. In 1 group, the IUD was inserted after entering the uterine cavity with uterine sounds. In the second group, The IUD was inserted directly without the use of uterine sounds. Pain was assessed using a visual analog scale (VAS) during and 30 minutes after the procedure. Subsequently, participants were reclassified into high (VAS ≥ 6) and low (VAS < 6) pain groups, and risk factors for high pain such as delivery history and uterine position were investigated. Those with uterine anomalies, chronic analgesic use, or procedural complications were excluded due to potential impact on pain perception.

RESULTS

When the pain scores of the uterine sound (n = 64) and without uterine sound (n = 64) groups were compared, high pain intensity during the procedure was higher in the without uterine sound group than in the uterine sound group (32.8% vs 17.2%, P = .041). No significant differences were found between the groups in terms of demographic characteristics. In the multiple regression analysis, significant factors identified for severe pain during the procedure were history of cesarean delivery (OR = 2.70, 95% CI [1.14, 6.41], P = .025) and nonuse of uterine sounds (OR = 2.54, 95% CI [1.06, 6.10], P = .036).

CONCLUSION

We demonstrated that the uterine sound method was less painful than the without uterin sound method. We recommend that IUD placement should be performed using the uterine sound method.