vasa previa血管: blood vessel; vascellum; ves ...前置: prepose; preposition; pre-胎盘血管前置: vasa previa of placenta帆状胎盘血管前置: vessel previa in velamentous placenta胎儿失血来自血管前置: fetal blood loss from vasa previa下载手机词典可随时随地查词查翻译