Natural History of Uterine Fibroids: A Radiological Perspective

This review aims to update our understanding of the radiological life cycle of fibroids, so that we may better counsel patients making difficult treatment decisions. Evidence for both pregnant and non-pregnant women have been considered separately.

Recent findings have shown that fibroids can undergo both growth and regression in non-gravid uterus. In pregnant women, fibroid growth is non-linear fashion, with the greatest growth occurring in the first 7 weeks of pregnancy. Growth in the later trimesters was significantly slower.

Fibroid growth, both in the intra- and inter-gravid states, is variable and can range from 18 to 120% per year. In the inter-gravid state, fibroids can grow or undergo spontaneous regression. Factors that can predict fibroid growth include the starting volume of fibroid, type of fibroid and age of patient. In the gravid state, fibroids appears to grow in a non-linear pattern, with the most rapid growth occurring in the first trimester. Factors affecting fibroid growth in pregnancy include the size of fibroids and number of fibroids.