<prompt> Blighted ovum is characterized by:Avascular villiSyncytial knotIntervillous haemorrhageIntracerebral haemorrhage  <response>: A blighted ovum is a feilized egg that implants but does not develop. In a blighted ovum, a gestational sac forms and grows; however, the embryo does not develop. So blighted ovum is also known as Anembryonic pregnancy. Blighted Ovum - Criteria Mean sac diameter 25 mm No yolk sac Embryo seen Avascular Villi Non Viable Pregnancy 