Adverse obstetric outcomes associated with sonographically identified large uterine fibroids

Study Objective: To determine the impact of sonographically identified large uterine fibroids (>5 cm in diameter) on obstetric outcomes. Design: Retrospective cohort study. Setting: University teaching hospital. Patient(s): Women with singleton gestations (n = 95) noted to have uterine fibroids on obstetric ultrasonography from September 2009 through April 2010 and age-matched controls (n = 95). Intervention(s): None. Main Outcome Measure(s): Obstetric outcomes including short cervix, preterm premature rupture of membranes, and preterm delivery. Result(s): Compared to women with no fibroids or small fibroids (≤5 cm), women with large fibroids (>5 cm) delivered at a significantly earlier gestational age (38.6 vs. 38.4 vs. 36.5 weeks). Short cervix, preterm premature rupture of membranes, and preterm delivery were also significantly more frequent in the large fibroid group, and were associated with number of fibroids >5 cm in diameter. Blood loss at delivery was significantly higher in the large fibroid group (486.8 vs. 535.6 vs. 645.1 mL), as was need for postpartum blood transfusion (1.1 vs. 0.0 vs. 12.2%). Conclusion(s): Women with large uterine fibroids in pregnancy are at significantly increased risk for delivery at an earlier gestational age compared to women with small or no fibroids, as well as obstetric complications including excess blood loss and increased frequency of postpartum blood transfusion.