Menstrual cycle irregularity and the incidence of nausea and vomiting after laparoscopy

Gender is an important risk factor for postoperative nausea and vomiting. Menstrual cycle phase has also been implicated as a further variable in female patients. It is not clear whether a history of an irregular menstrual cycle is a significant variable and studies to date have not examined this. The influence of an irregular menstrual cycle on nausea and vomiting after laparoscopy was evaluated in a blinded, prospective, observational study. One hundred and fifty-nine patients scheduled for laparoscopy and dye investigation were included. Anaesthetic technique and postoperative analgesia were standardised. In comparison with patients who had a regular cycle, an irregular menstrual cycle increased the incidence of nausea or vomiting from 20.5% to 40.5% (absolute difference 20%; 95% CI 0.03-0.37, p = 0.01). Other variables were similar between the groups. An irregular menstrual cycle appears to increase the risk of postoperative nausea and vomiting.