Prenatal diagnosis of solid placental masses: the value of color flow imaging.

OBJECTIVES: To determine the value of color flow imaging in the prenatal differentiation of solid placental masses protruding from the fetal surface of the placenta.
METHODS: Seven pregnancies in which a large solid mass was seen on the fetal surface of the placenta were prospectively studied. Color flow imaging was used to identify vessels within the mass and the prenatal ultrasound finding correlated with placental pathology.
RESULTS: Postpartum examination of the placenta revealed four cases of chorioangioma, two cases of subchorionic thrombohematoma and one case of subamniotic hematoma. Prenatal ultrasound using color flow imaging correctly identified all cases of placental chorioangioma by the demonstration of blood flow within the mass. Conversely, absence of blood flow signals was invariably documented in both cases of subchorionic thrombohematoma and in the single case of subamniotic hematoma. Among the four cases of chorioangioma, two developed complications requiring delivery. No complications were noted in cases of avascular placental masses in this series.
CONCLUSIONS: Color Doppler ultrasound plays an important role in the prenatal evaluation of solid placental masses. This technique allows the identification of those cases at increased risk of pregnancy complications which need close monitoring throughout gestation.