Could antispasmodic drug reduce pain during hysterosalpingo-contrast sonography (HyCoSy) in infertile patients? A randomized double-blind clinical trial.

Objective: To assess the effectiveness of an antispasmodic drug, hyoscine-N-butylbromide, in reducing pain during hysterosalpingo-contrast sonography (HyCoSy).

Methods: Eight hundred and sixteen patients undergoing HyCoSy were randomized to receive 10 mg hyoscine-N-butylbromide (n = 408) or placebo (n = 408) per os, 30 min before the procedure, in a double-blind randomized controlled trial. Immediately after the procedure, the patient was asked to describe any pain experienced in comparison with pain usually suffered during the menstrual cycle, and the operator assigned a pain score between 0 and 4 as follows: 0 (no reaction or discomfort), 1 (slight pain, less than menstrual pain), 2 (moderate pain, exceeding menstrual cramps but no vasovagal reaction), 3 (vasovagal reaction or pain requiring observation in a hospital) and 4 (vasovagal reaction or pain requiring resuscitation). The primary aim was to estimate the difference in pain score, considered as a categorical value, between the active arm of the trial and the control group. The secondary aim was to evaluate if pain is related to tubal patency.

Results: There was no difference in pain score between the hyoscine-N-butylbromide group and the placebo group (P = 0.807). There was a negative correlation between pain and tubal patency, regardless of treatment group (P < 0.0001).

Conclusions: Administration of 10 mg antispasmodic drug hyoscine-N-butylbromide does not reduce pain in patients undergoing HyCoSy.