A blighted ovum refers to a miscarriage that occurs in the first few weeks of pregnancy.
It is estimated that only about 2/3 of female eggs that are fertilized result in detectable pregnancies. The other 1/3 of fertilized eggs spontaneously abort or die. Another name for a female egg is an ovum. A blighted ovum usually occurs before a woman even knows she is pregnant.
A blighted ovum is abnormal. Nature selects those people that are able to survive. Many of the fertilized eggs that die this early have severe genetic defects. These eggs cannot develop properly and end up dying. This condition seems to occur more often in older women. Older women have a higher risk of delivering children with genetic disorders, such as Down syndrome.
The main risk of this condition is usually the mental distress caused by discovery that the woman is or was pregnant. Repeated early egg deaths may indicate a genetic or physical disorder in the parents. Rarely, a specific problem may be causing multiple early egg deaths, such as low hormone levels.