The menstrual cycle and acute appendicitis

Objective: To examine the influence of the menstrual cycle on the incidence and presentation of acute appendicitis. Design: Retrospective study. Setting: University hospital, Israel. Subjects: 144 women of child bearing age operated on for suspected acute appendicitis and subdivided according to the menstrual phase during which they presented. Main outcome measures: The final diagnoses, clinical presentation, and laboratory data. Results: There were no significant differences in the incidence of acute, gangrenous, or perforated appendicitis in patients operated on during the various phases of the menstrual cycle. During menstruation, however, a normal appendix not accompanied by other disease was found significantly more often (p = 0.04). Clinical presentation, physical findings, and laboratory results did not vary throughout the menstrual cycle except for the 'classic shifting pain' which was significantly more common during the luteal phase. Conclusions: Acute appendicitis occurs randomly during the various phases of the menstrual cycle. The incidence of operations for uninflamed appendixes may be higher during the menstrual phase. Significantly more negative laparotomies are done during the menstrual phase, which suggests the existence of a functional disorder that mimics acute appendicitis.