Family history as a risk factor for development of uterine leiomyomas. Results of a pilot study

To determine (1) the association between maternal history of leiomyomas and those in women under the age of 50, and (2) the ability of subjects to report a family history of leiomyomas.

We performed a hospital-based, case-control study. The cases were women with pathologically confirmed leiomyomas, and the controls were women with no leiomyomas after pathologic examination of the uterus or by transvaginal ultrasonography. All women were sent a questionnaire regarding potential risk factors for the development of leiomyomas.

Eighty-one of 169 (47.9%) cases and 103 of 214 (48.1%) of controls completed the questionnaire. By multiple logistic regression, significant risk factors for the presence of leiomyomas were maternal history (odds ratio = 2.85, confidence intervals 1.25-6.52) and reduced parity (odds ratio = 0.75, confidence intervals .57-.98). Increasing age was nearly significant as a risk factor (odds ratio = 1.07, confidence intervals 1.00-1.15). Of the subjects, 24% did not know the maternal history of leiomyomas, while 29% and > 50% were not aware of this history in a sister or grandmother, respectively. Extended family histories of leiomyomas could not be ascertained by this questionnaire-based study.

Our results suggest that a maternal history of leiomyomas might be the largest risk factor for development of leiomyomas in a largely Caucasian population of women. Further studies are needed to better understand the possible genetic contribution to the development of uterine leiomyomas. Given the ascertainment bias inherent in second-hand maternal histories, future studies should assess maternal leiomyoma presence by ultrasonographic or pathologic evaluation.