Introduction
Vasa praevia is defined as a condition in which the cord vessels are present in the membranes covering the internal cervical os. The prevalence of vasa praevia is approximately 1 in 2500 pregnancies. In 90-95% of these cases, vasa praevia is associated with placenta praevia, a low-lying, bilobed, or succenturiate lobe placenta, or with velamentous umbilical cord insertion [1]. An abnormal position and/or morphology of the placenta should alert the physician to rule out vasa praevia. If the position and morphology of the placenta are normal on ultrasound examination, the possibility of foetal vessels running over the internal cervical os should be assessed for diagnosis of vasa praevia. In such cases, foetal vessels usually run over the internal cervical os and continue to the main placenta on the opposite uterine wall. If the placenta and umbilical cord insertion are on the same side of uterine wall, foetal vessels could potentially meander and run over the internal os. Such vasa praevia is extremely rare and difficult to diagnose prenatally. Here, we report a case of vasa praevia with meandering foetal vessels despite placenta and umbilical cord insertion on the same side of uterine wall.