[1] D’Ercole C, Cravello L, Boubli L, et al. Large chorioangioma associated with hydrops fetalis:prenatal diagnosis and management [J].Fetal Diagn Ther, 1996, 11(5):357-60. [2] Ahmed N, Kale V, Thakkar H, et al. Sonographic diagnosis of placental teratoma[J].J Clin Ultrasound, 2004, 32(2):98-101. [3] Gramellini D, Pedrazzoli G, Sacchini C, et al. Color Doppler ultrasound in prenatal diagnosis of umbilical cord angiomyxoma. Case report [J]. Clin Exp Obstet Gynecol, 1993, 20(4):241-4.
