Prescription of Chinese herbal products is associated with a decreased risk of uterine fibroids: A population-based cohort study

The finding of a decrease in subsequent fibroid-related operation following the use of Chinese herbal products (CHPs) has led to speculation that CHPs might play a role in uterine fibroids prevention. This study provides an overview of uterine fibroids incidence, comparing CHP users with those who do not use CHPs, referred to as non-CHP users. The results can provide information to clinicians for counseling women about the preventive use of CHPs. A total of 52,151 women (20–45 years of age) were recruited from a nationwide 1-million-person representative sample of those covered by National Health Insurance in Taiwan and were followed from 2000 to 2013. Exact matching was performed for comparative analysis. The age-specific hazard ratios (HRs) of uterine fibroids in relation to either CHP or the phytoestrogen use were calculated with multivariate Cox proportional hazard regression. More than 71% of patients had used a CHP at some point previously. The overall incidence density rate of uterine fibroids for non-CHP users was estimated at 27.5 per 1000 patient-years. The corresponding values for CHP and the phytoestrogen users were lower than those of the non-CHP group (CHP group = 15.5; the phytoestrogen group = 12.5 per 1000 patient-years). The covariate adjusted HRs for uterine fibroid were 0.73 (95% confidence interval [CI] 0.63–0.85) and 0.65 (95% CI 0.52–0.82) in women using CHPs and the phytoestrogen, respectively. CHPs seem to contribute to a decreased risk in developing uterine fibroids. Although the mechanism of action of these products is unclear, their use as a preventive agent for uterine fibroids might be taken into consideration.