The use of mifepristone in abortion associated with an increased risk of uterine leiomyomas

To investigate the association between widespread use of mifepristone in abortions and risk of uterine leiomyomas. We conducted a case-control study of 305 patients with uterine leiomyomas between January 2011 and July 2012; 311 women with ordinary vaginitis were selected as controls during the same period. Data were collected by questionnaires (including past history, life history, menstruation history, reproductive history, abortion history, the use of mifepristone, and uterine leiomyomas risk factors) and calculated by univariate and multivariate conditional logistic regression analyses; odds ratios and its 95% confidence interval were calculated to estimate the risk for uterine leiomyomas. Abortion with mifepristone was one of the risk factors for uterine leiomyomas, and the risk increased with increasing frequency of mifepristone use. Family history of uterine leiomyomas, body mass index, age at menarche, number of full-term delivery, and medical abortion history were also correlated with uterine leiomyomas. The use of mifepristone in abortion will increase the risk to develop uterine leiomyomas.