The prevalence of uterine fibroids varies significantly among the studies, with a range from 4.5% to 68.6%. This wide variance of prevalence is affected by the methods of diagnosis used from a self-report to a pelvic exam, which are the least specific, to imaging and surgical findings that are more accurate.
Conventional management includes short term use of GnRH agonist/antagonists. Long term management includes the use of ulipristal acetate. Various radiologic and surgical interventions are available. Fortunately, most fibroids do not need treatment because the size and location are not causing significant or intolerable symptoms.
This systematic review is based on 60 papers.2 The studies reviewed vary in type and include both prospective cohort and case-control studies. Other problems in the review are that the majority are registry-based reports and the method of diagnosis used in each study varies, with not all using imaging studies, but rather history and/or pelvic exam and/or surgical findings.
Thirty categories of risk factors were evaluated and the following issues were identified as having a reasonably great impact on fibroid growth:
- Black race is associated with a two to threefold increased risk.
- Age is associated with a 10-fold increased risk for women age 40 and older, compared with those aged 20-30 years.
- Family history of fibroids is associated with a threefold increased risk.
- Time since last birth is associated with a two- to threefold increase in women who gave birth more than 5 years prior. Higher parity is associated with a reduced risk. Specifically, there is an 80% risk reduction in women with three or more deliveries compared with nulliparous women.
- Uterine fibroids are three to five times more common in premenopausal women compared with postmenopausal women.
- Smoking lowers the risk of fibroids by one third when the BMI is under 22.2 kg/m2
- Current use of oral or injectable contraception is associated with two thirds reduced risk.
- Women with hypertension have a fivefold likelihood of being diagnosed with fibroids.
- The intake of food additives and soybean increases the risk of fibroids.2
Commentary: Although outside the content available within this systematic review, I think it’s useful to mention two studies on natural therapies demonstrating potential use in both shrinking uterine fibroids and reducing symptoms-green tea extract and black cohosh.
In the green tea study3, 22 women were randomized to receive green tea extract and 17 to receive placebo. Study subjects were randomized to oral green tea extract (45% epigallocatechin gallate= EGCG) or placebo of brown rice, daily, for 4 months. Each green tea capsule contained 95% polyphenols and 45% EGCG. Women received two capsules daily of either green tea or placebo over the 4 month period. Of the final 11 women who completed the placebo group, fibroid volume increased by 24.3% over the study period; Of the final 22 women in the green tea extract group, a significant uterine fibroid total volume reduction of 32.6% was observed. The green tea extract group also had a significant reduction in fibroid specific symptom severity of 32.4% and a significant improvement in HRQL of 18.53% compared to the placebo group. Anemia improved significantly by 0.7 g/dL in the green tea group and the average blood loss significantly decreased from 71 mL/month to 45 mL/month. There were no adverse effects or endometrial hyperplasia or pathology in either group. Crinum latifolium has been a part of Vietnamese history and folklore for generations. Numerous benefits of Crinum have been reported over the years but none had been clinically studied until recently. Of the 12 varieties of Crila, one specific variety in particular, the C. latifolium “Tram,” named after the leading researcher, has been studied in women with uterine fibroids. A 3-month study of 195 women with uterine fibroid tumors was conducted in three hospitals in Vietnam in 2007. The C. latifolium decreased the size or stopped the growth of the fibroid tumors in 79.5% of the women. In 20.5%, tumor growth continued at a very slow rate. Whereas a heavy menstrual flow was reported by 36% of the women before taking Crila, this had decreased to only 1% after treatment. Side effects reported were slight, including nausea, headache, vaginal dryness, and hot flashes, but these decreased over time.4
An original menopause study, published in 2007 enrolled 244 Chinese women aged 40-60 years with menopause symptoms who were treated with either black cohosh extract, 40 mg/day (n=122) or tibolone 2.5 mg/day (n=122) for 3 months. This study investigated the subset of women (n=62) who had at least one uterine fibroid at the onset of the study and compared the effect of black cohosh extract (n=34) on fibroid size compared with tibolone (n=28), using transvaginal ultrasound.5
The patients were treated for 12 weeks with iCR or tibolone. Study visits were at entry, 4 weeks and 12 weeks. Clinical variables including the Kupperman Index (KI), vital signs, body weight, co-existing diseases, adverse events and co-existing medications were recorded. In addition to blood samples for follicle stimulating hormone (FSH), estrogen, standard hematology and biochemistry and urine samples, transvaginal ultrasound was also performed before onset of study and at the end of treatment.5
1. Cardozo, E., et al. Am J Obstet Gynecol. 2012 Mar; 206(3).
2. Stewart E.A., et al. BJOG. 2017; 124:1501-1512.
3. Roshdy, E., et al., et al. Int J Womens Health. 2013; 5:477-486.
4. Xi, S., et al. Evidence-Based Complementary and Alternative Medicine 2014.