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.