Calvo JAS, del Valle Rubido C, Rodríguez‐Miguel A, et al. - Via performing a single‐blind stratified randomized clinical trial with masked assessment by a third party, researchers sought to compare the effect of inhaled nitrous oxide (INO) on pain control during in‐office hysteroscopy with 1% lidocaine paracervical infiltration and no analgesic. According to the purpose of the hysteroscopy (biopsy, polypectomy or tubal sterilisation), they stratified the patients into three groups; thereafter the patients were assigned to different treatment groups through a permuted‐blocks randomisation within strata. Among a total of 314 included women, 105 were assigned to INO, 104 to 1% lidocaine and 105 to no analgesic. Relative to 1% lidocaine, INO had equivalent effectiveness in pain control for in‐office hysteroscopy and had better tolerability. The least recommended clinical option was no‐analgesia as poorer results were identiifed in the group with no‐analgesia.