Assertion: umbilical cord's vessel | /r/HasProperty | marginal sinus previa
Facets:
Source sentences:
text: Vasa previa may be difficult to visualize at transabdominal US because of maternal obesity, abdominal wall scarring, an incompletely filled maternal bladder, or a tortuous course of the umbilical vessels that may be difficult to follow (marginal sinus previa) can mimic vasa previa ( Vasa previa may be difficult to visualize at transabdominal US because of maternal obesity, abdominal wall scarring, an incompletely filled maternal bladder, or a tortuous course of the umbilical vessels that may be difficult to follow ( Fig 11 )