Blighted ovum, or anembryonic pregnancy
, is when the ovum has gone through the insemination process with a spermatozoon, but for as yet unknown reasons, does not initiate the process of cell division which creates a baby. We term the gestational sac as "empty" as, on ultrasound, there is nothing inside it. Ultrasound is the only means by which we can detect a blighted ovum, given that all the normal signs of pregnancy
are still present. A blighted ovum is generally ejected during a miscarriage
, but does not preclude the possibility of having a normal pregnancy later.