1. Umbilical cord, velamentous insertion, vasa previa, true knot, nuchal cord, abdominal insertion, sigle umbilical artery, umbilical vein, cord mass, etc; 脐带：帆样附着，前位血管，脐带真结，颈部脐带，腹部脐带附着，单只脐动脉，脐静脉，脐带肿块等；