Abstract: Objective:To explore the clinical value of prenatal ultrasonography in the diagnosis of the vasa previa.Methods:The ultrasonographical features of the vasa previas in 13 cases were retrospectively analyzed,and the postpartum results were followed up.Results:Among 13 pregnant women with vasa previa,the velamentous insertion type in 8 cases,accessory placenta type in 3 cases,bilobate placenta type in 1 case and umbilical placental edge attachment type in 1 case were identified.Ten cases were correctly diagnosed by ultrasonic examination,the accuracy rate of which was 76.92%(10/13).The missed diagnosis in 1 case and misdiagnosis in 2 cases were found.The vascular branch under the membranes across or close to intracervical mouth was the typical ultrasonogram characteristics of vasa previa,and the spectral doppler of vasa previa was the typical umbilical artery blood flow spectrumConclusions:The diagnositic accuracy of prenatal ultrasonography in vasa previa is higher,which has important clinical application value.