Importance: Fibroids are benign uterine tumors that can cause significant morbidity. Knowledge on fibroid prevalence, especially in the asymptomatic population and in Asian and Hispanic or Latina individuals, is limited, and a better understanding of affected groups will improve timely diagnosis and motivate appropriate recruitment in clinical trials to reduce health disparities.
Objective: To estimate the prevalence of fibroids in a diverse cohort of female individuals.
Design, setting, and participants: This cross-sectional study included female individuals not seeking treatment for fertility or other conditions who were prospectively recruited in an academic medical center in San Francisco, California. Effort was made to recruit an equal proportion of participants from 4 large racial and ethnic groups in the United States (Asian-Chinese, Black or African American, Hispanic or Latina, and White) and across 4 equal age groups between 25 and 45 years. All participants reported regular menses (21-35 days), had not used estrogen- or progestin-containing medications in the 3 months prior to enrollment, and denied history of pelvic surgery. The assessment of ultrasonography results was part of an ongoing longitudinal cohort, with initial recruitment from October 2006 to September 2012. Data analysis was performed in April to September 2022.
Main outcomes and measures: Fibroid presence and burden as assessed by transvaginal ultrasonography.
Results: A total of 996 female participants were included in the analysis, including 229 (23.0%) Asian-Chinese, 249 (25.0%) Black or African American, 237 (23.8%) Hispanic or Latina, and 281 (28.2%) White individuals. Mean (SD) age was 34.8 (5.7) years in Asian-Chinese participants, 35.4 (6.1) years in Black or African American participants, 34.8 (5.3) years in Hispanic or Latina participants, and 35.3 (5.0) years in White participants. Fibroids were present in 21.8% (95% CI, 16.7%-27.8%) of Asian-Chinese participants, 35.7% (95% CI, 29.8%-42.0%) of Black or African American participants, 12.7% (95% CI, 8.7%-17.6%) of Hispanic or Latina participants, and 10.7% (95% CI, 7.3%-14.9%) of White participants. Black or African American and Asian-Chinese participants were more likely to have fibroids than White participants (Black or African American: adjusted odds ratio [OR], 4.72 [95% CI, 2.72-8.18]; P < .001; Asian-Chinese: adjusted OR, 3.35 [95% CI, 1.95-5.76]; P < .001). In those with fibroids, the proportion with multiple fibroids were 48.3% in Black or African American participants, 33.3% in White participants, 33.3% in Hispanic or Latina participants, and 26.0% in Asian-Chinese participants (P = .06). The largest mean (SD) fibroid diameter was 3.9 (1.9) cm in Black or African American participants, 3.2 (1.6) cm in Asian-Chinese participants, 3.2 (1.6) cm in White participants, and 3.0 (1.4) cm in Hispanic or Latina participants (P = .03).
Conclusions and relevance: In this study of female participants in a nonclinical setting, Black or African American and Asian-Chinese participants were disproportionately affected by uterine fibroids. Hispanic or Latina participants had similar fibroid burden to White participants.