Objective: To evaluate the effectiveness of lidocaine gel in pain relief during endometrial sampling procedure (ESP).

Materials and Methods: A double-blinded randomized controlled trial was conducted at the gynecology clinic of Thammasat University Hospital between January and June 2020. Women aged over 35 years old with abnormal uterine bleeding were recruited. The participants were equally randomized assigned into two groups. The study and the control group received 3 mL of 2% lidocaine gel and lubricant gel locally applied at the cervix five minutes before performing ESP, respectively. The visual analog scale (VAS) was used to evaluate pain scores. Results were collected at five timeframes, insertion of a speculum, at the first, second, and third ESP, and five minutes post-procedure.

Results: One hundred and ten women, with 55 in each group, were eligible for randomization. Mean age of participants was 50 years old. Half of the cases (46/110) had complaint of irregular vaginal bleeding. Demographic characters of both groups were comparable. VAS at five timeframes in the study group and the control group were 19/23, 51/51, 56/60, 60/64, and 20/18, respectively, without statistical significance. The severe

pain score was highest in the third ESP for both groups. Three cases of endometrial cancer were diagnosed. Ten percent (11/110) of tissue samples were inadequate for evaluation.

Conclusion: Application of lidocaine gel at the cervix could not effectively reduce pain during ESP.