Fibroids in pregnancy--common but poorly understood.

UNLABELLED: Uterine fibroids are the most common benign tumors in women, occurring in approximately 20% to 30% of women of reproductive age. They are therefore common in pregnancy. The true incidence of fibroids during pregnancy is, however, unknown, but reported rates vary from as low as 0.1% of all pregnancies to higher rates of 12.5%. It seems that pregnancy has little or no effect on the overall size of fibroids despite the occurrence of red degeneration in early pregnancy. Fibroids, however, affect pregnancy and delivery in several ways, with abdominal pain, miscarriage, malpresentation, and difficult delivery being the most frequent complications. The size, location, and number of fibroids and their relation to the placenta are critical factors. Ultrasound scanning plays a central role in diagnosing and monitoring fibroids during pregnancy and in determining the relative position of the fibroids to the placenta. It is equally useful for detecting heterogeneous echo patterns associated with the appearance of pain in pregnancy. Color flow Doppler scanning differentiates fibroids from myometrial thickening, which may be mistaken for fibroids. Few treatment options are available during pregnancy, but in carefully selected patients, myomectomy has been performed successfully without jeopardizing pregnancy outcome. A successful pregnancy and delivery is common with appropriate surveillance and supportive management.

TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians

LEARNING OBJECTIVES: After completion of this article, the reader should be able to summarize the influence of pregnancy on fibroids, to explain the influence of fibroids on pregnancy, and to outline the management of fibroids during pregnancy.