blighted ovum

blighted ovum A fertilized ovum (egg) that did not develop or whose development ceased at an early stage, before 6 or 7 weeks of gestation. On the ultrasound examination of a blighted ovum, only the gestational sac that normally surrounds the embryo can be seen. There is usually no embryo inside the gestational sac. A blighted ovum is a form of early spontaneous abortion (miscarriage).