The impact of menstrual cycle phases on postoperative nausea and vomiting in premenopausal women undergoing laparoscopic gastrointestinal surgery: a secondary analysis of a randomized controlled trial

Purpose This study aimed to investigate the impact of the menstrual cycle phase on Postoperative Nausea and Vomiting (PONV) in premenopausal women undergoing laparoscopic gastrointestinal surgery. Methods This study was a retrospective cohort analysis of premenopausal women with regular menstrual cycles who underwent laparoscopic gastrointestinal surgery from a prospective randomized controlled trial. Menstrual history was used to determine the surgery-to-ovulation interval and then the cycle phase (non-luteal or luteal). The primary outcome was PONV during 0–24 h post-surgery. Secondary outcomes included PONV during 25–120 h post-surgery and the incidence of nausea, emetic episodes, and postoperative antiemetic medications across both timeframes. Sensitivity analyses evaluated the association between the surgery-to-ovulation interval and outcomes, as well as the association between the cycle phase (follicular, ovulatory, or luteal) and outcomes. Results A total of 240 women were enrolled, with 119 in the non-luteal phase and 121 in the luteal phase. The incidence of PONV between the non-luteal and luteal groups was not significantly different during 0–24 h post-surgery [44.5% vs. 47.1%, adjusted odds ratio 1.10 (95% confidence interval: 0.62–1.95), adjusted P = 0.735]. There were no significant differences in PONV, nausea, emetic episodes, or postoperative antiemetic medications between groups during 0–24 and 25–120 h after surgery. Sensitivity analyses showed no significant association between surgery-to-ovulation interval and outcomes, nor between the cycle phase (follicular, ovulatory, or luteal) and outcomes. Conclusion The menstrual cycle phase did not affect the occurrence of PONV either within 0–24 h or 25–120 h after laparoscopic gastrointestinal surgery in premenopausal women.