Early normal menstrual cycle pattern and the development of uterine leiomyomas.

It is unclear if women who develop uterine leiomyomas have had menstrual regularity or irregularity in their reproductive life. This case-control study examines the recalled menstrual cycle patterns throughout the reproductive life among women requiring hysterectomy for myomas. One hundred twenty-two women with myomas and 244 age-matched healthy controls without myomas were enrolled in Japan. The incidence of normal menstrual cycle pattern in their teens among patients with myoma was significantly higher than that among healthy controls (p < 0.01). The subset results for parous women were the same as those for all subjects. The size of the uterus in myoma patients with teenage menstrual regularity was not larger than in those with teenage menstrual irregularity. Women who developed myomas later in life tended to have early normal menstrual cycle pattern. Early menstrual regularity may enhance leiomyoma growth in early reproductive life.