The NIEHS Uterine Fibroid Study was designed to:
- determine how many women have fibroids
- identify risk factors for fibroids
- identify biological changes in tumor tissue compared with normal uterine muscle
- describe women's experience of symptoms associated with fibroids and how they change over time
A randomly selected sample of 35-49 year-old women members of the George Washington University Health Plan were invited to participate in the study. Nearly 1,500 women participated in the initial enrollment and screening during 1996-1999. Postmenopausal women were interviewed about prior diagnoses of fibroids, and premenopausal women were screened for fibroids with pelvic ultrasound (transvaginal and transabdominal). Extensive information was collected by telephone interview and self-administered questionnaires. Premenopausal women were asked to maintain a seven-week prospective menstrual diary and to make a clinic visit at which time blood was drawn . Weight, waist and hip circumference, and blood pressure were measured.
Premenopausal women were followed by telephone interview for new diagnoses of fibroids, symptom change and treatment decisions. The first followup was conducted in 2001-02 and the final follow-up, in 2004-05.
Uterine leiomyomata, also known as fibroids, are the leading indication for hysterectomy in the United States. Despite the morbidity and high medical costs associated with fibroids, there has been little epidemiologic study of this condition. These benign tumors are hormone-dependent, develop after puberty and regress after menopause. Both estrogen and progesterone are considered important stimulants, or at least permissive factors for tumor growth. To address the need to understand this condition in order to develop nonsurgical treatments and eventually to prevent the condition, collaborators designed the Uterine Fibroid Study.