Background Understanding predictors of pain with gynaecological procedures may facilitate individualised counselling and pain management. We aimed to study the effect of dysmenorrhoea on intrauterine device (IUD) insertion pain.

Methods This was a planned secondary analysis of a randomised trial evaluating self-administered lidocaine gel versus placebo for IUD insertion pain. We included those participants who reported menses in the past 3 months. We assessed dysmenorrhoea (in the past 3 months) and procedural pain using a 100 mm visual analogue scale (VAS). We categorised dysmenorrhoea as none/mild (<40 mm), moderate (40–69 mm) or severe (≥70 mm). We assessed participant pain scores at speculum insertion, tenaculum placement, IUD insertion, and overall. We compared median procedural pain scores by dysmenorrhoea group with three-way and post hoc pairwise analyses.

Results We analysed 188 participants. Demographic characteristics were similar among the three dysmenorrhoea groups. Pairwise comparisons revealed higher median procedural pain scores in the severe dysmenorrhoea group compared with the none/mild dysmenorrhoea group at speculum insertion (25 mm vs 8 mm; p=0.007), tenaculum placement (51 mm vs 31 mm; p=0.04) and IUD insertion (74 mm vs 61 mm; p=0.04). Overall pain did not differ among the three groups (p=0.32).

Conclusions Patients with severe dysmenorrhoea experienced increased pain with all aspects of IUD insertion, including speculum and tenaculum placement, compared with those with only mild or no dysmenorrhoea. Clinicians may consider this finding when providing individualised counselling and pain management for patients undergoing IUD insertion and other gynaecological procedures. Larger studies are needed to validate the effect of dysmenorrhoea severity on pain throughout IUD insertion.