Natural vs. D&C. 'blighted ovum' is an older name for anembryonic pregnancy, in which a gestational sac/intrauterine pregnancy is seen but no embryonic pole. It's an abnormal pregnancy that is treated either by allowing natural miscarriage, or by d&c.
Blighted ovum. Depending upon how far along you are in the pregnancy you can either wait for a spontaneous miscarriage or can have a d&c. If a surgical procedure is done you can have chromosomal analysis done to determine the cause of the miscarriage.