<prompt> Blighted ovum is:Synaptic knobsAvascular villiIntervillous hemorrhageNone of the above  <response>: In missed aboion ultrasound will show a gestational sac smaller than expected with irregular and crenated margin. An embryonic pregnancy blighted ovum is considered when there is a gestational sac more than 16 mm in diameter without a foetal node.refer pgno:146 sheila 2 nd edition 