Myomas in Pregnancy: A Review

Abstract

Uterine myoma or uterine fibroid is a mass of compacted smooth muscle and fibrous tissue that grows on the wall or sometimes on the outside of the uterus, usually appearing as benign, monoclonaltumors of the myometrium that contain collagen, fibronectin and proteoglycan. In this article, we review the etiology, incidence in pregnancy, risk factors, types and locations, degenerative changes, growth and complications of myomas in pregnancy as well as the role of ultrasound scan technology in its management. We searched databases for information and identified articles with sufficient information onmyomas in pregnancy and excluded those that did not specifically focus on our area of discourse. Our findings show that, although causes of myomas remain unknown, several factors including age, late reproductive years, race, nulliparity, obesity, early menarche menopause and smoking are predisposing factors. Other unestablished factors are diet, exercise, oral contraceptives, hormone replacement therapy and genetic make-up. Women, 35 years and above are more susceptible and incidence rate in pregnant women ranges from 1.5-10%. Types include intramural (70%), submucosal (10%), subserosal (20%), pedunculatedsubserous (minimal), cervical (minimal) and retroplacentalmyomas. Sonography reveal that degenerative changes in myomas may be hyalinic, necrotic, cystic, fatty, haemorrhagic, calcified or sarcomatous. Only a few cases of myomas increase with pregnancy, while majority remain stable and may even decrease, but with higher risk of complications, fetal injury and caesarean delivery. Early and routine ultrasound scan may be encouraged in all pregnancies for early detection of myomas for the purpose of better obstetric management.