On USG, blighted ovum is diagnosed when the gestational sac is :
High-Yield Explanation
Blighted ovum/ Silent pregnancy: It is a sonographic diagnosis. There is absence of fetal pole in a gestational sac with diameter of 3 cm or more. Uterus is to be evacuated once the diagnosis made. Reference: Dutta's Textbook of Obstetrics 7th edition page no 161