Umbilical cord insertion to the lower uterine segment is a risk factor for vasa previa.

The perinatal mortality rate of vasa previa is high if it is not prenatally diagnosed. Systematic strategies for vasa previa screening have been recommended. In this paper, three cases of vasa previa diagnosed prenatally, with umbilical cord inserted to the lower segment of the uterus, are presented. It should be considered that umbilical cord insertion to the lower uterine segment is a high risk for vasa previa. Ultrasound screening for cord insertion will make it possible to do efficient and certain detection of vasa previa.