Fibroids can dramatically increase in size during pregnancy. This is thought to occur because of the increase in estrogen levels during pregnancy. After pregnancy, the fibroids usually shrink back to their pre-pregnancy size. They typically improve after menopause when the level of estrogen, the female hormone that circulates in the blood, decreases dramatically. However, menopausal women who are taking supplemental estrogen (hormone replacement therapy) may not experience relief of symptoms.
Uterine fibroids are the most common tumors of the female genital tract. You might hear them referred to as “fibroids” or by several other names, including leiomyoma, leiomyomata, myoma and fibromyoma. Fibroid tumors of the uterus are very common, but for most women, they either do not cause symptoms or cause only minor symptoms.
Twenty to 40 percent of women age 35 and older have uterine fibroids of a significant size. African American women are at a higher risk for fibroids: as many as 50 percent have fibroids of a significant size. Uterine fibroids are the most frequent indication for hysterectomy in premenopausal women and, therefore, are a major public health issue.