Are ultrasonographic myoma characteristics associated with blood loss at delivery?

OBJECTIVES: The presence of myomas in pregnancy is associated with greater blood loss at delivery. The aim of this study was to evaluate whether the sonographic characteristics of myomas can predict blood loss at delivery in women with large myomas. METHODS: Among women who underwent second-trimester ultrasound screening at our department between January 1996 and December 2004, 251 had at least one myoma with a mean diameter > or = 5 cm. Number of myomas (single vs. multiple), maximum diameter of the largest myoma, sum of the maximum diameter of each myoma, change in size of myomas between first and last scan, and location in relation to the placenta and to the presenting part of the fetus (above or below) were analyzed in relation to blood loss at delivery and severe postpartum hemorrhage (> or = 1000 mL). RESULTS: Multivariate analysis showed that the presence of multiple myomas was the only parameter independently associated with amount of blood loss at delivery (P = 0.003). The association between the presence of multiple myomas and severe postpartum hemorrhage was of borderline significance for the statistical power of this study (P = 0.08). CONCLUSIONS: In women with large myomas, the presence of multiple tumors is independently associated with heavier blood loss at delivery but not with postpartum hemorrhage of > or = 1000 mL.