Patterns of growth of uterine leiomyomas during pregnancy. A prospective longitudinal study.

In a prospective study 32 leiomyomas (fibroids) in 29 pregnant women were examined with ultrasound every 3-8 weeks. Each patient had between 3 and 6 scans (mean 4.4) during the course of pregnancy, and 13 patients had a final scan at 6 weeks postpartum. An individual growth curve was established for each tumour and the patterns of growth were analysed. No increase in size during the pregnancy was observed in 25 fibroids (78%). Only 7 (22%) increased in size but by no more than 25% of the initial volume. At 6 weeks postpartum the size of the fibroids did not differ significantly from the size during pregnancy.