Though a blighted ovum can sometimes be the result of low hormone levels in the body, the major cause of the condition appears to be chromosomal. A blighted ovum is thought to occur when the chromosomes making up the fetus become defective or disordered, resulting in severe genetic defects. Your body recognises these chromosomal abnormalities and chooses to end the pregnancy. Chromosomal abnormalities can occur for many reasons. Sometimes, the egg or sperm that are joined during fertilization have defective cells. Other times, chromosomes can become improperly arranged during division of the fertilized egg. [more]
A blighted ovum is referred to as an "abnormality" for this reason.
In one study of multiple pregnancies carried out over a period of four years, 41 cases of abnormal multiple pregnancies were diagnosed successfully by ultrasound. These included several rare combinations of abnormalities. The most frequent was a normal pregnancy and a synchronous blighted ovum. [more]