As of May 2015, doctors have not definitively found the cause for fibroid growth, according to Mayo Clinic. Research indicates that hormones, genetic changes and substances helping the body conserve tissue levels are all likely to play a role.
Cellular analysis of fibroid cells show alterations from the genes in typical muscle cells in the uterus. Some research has demonstrated that certain families are more likely to develop fibroids than others. Also, identical twins have an elevated risk of fibroids in comparison to fraternal twins, notes Mayo Clinic.
Insulin-like growth factor is just one of many substances that the body uses to keep tissue levels constant. Some research indicates that these substances possibly influence the development and growth of fibroids. Two of the hormones that spur uterine lining development during menstrual cycles, progesterone and estrogen, also appear to spur fibroid growth. Fibroid tumors have more receptors for these two hormones than typical muscle cells in the uterus, reports Mayo Clinic.
Treatments for fibroids vary widely, ranging from waiting to see if they grow to surgical removal. Because fibroids are not cancerous and only seldom have an effect on pregnancy, intervention may not be necessary, particularly since they often get smaller after menopause, when estrogen and progesterone production declines, states Mayo Clinic.