Prenatal ultrasonographic detection of abdominal and pelvic tumors: impact on management.

An abdominal or pelvic tumor in very seldom detected in a prenatal ultrasound examination. The most commonly detected tumors are, in order of decreasing frequency, sacrococcygeal teratomas, neuroblastomas and kidney tumors. According to the present state of the art, diagnosis of a sacrococcygeal teratoma only leads to specific monitoring of the pregnancy, because an early delivery or delivery by cesarean section will be necessary in some cases to improve the prognosis of child and/or mother. For other types of tumors investigations and actions should be delayed until after birth.