What causes miscarriage?

Many causes: Most early miscarriages are due to chromosomal defects in the fetus. See this site of a longer list of the causes. http://www.webmd.com/infertility-and-reproduction/guide/pregnancy-miscarriage.

Genetics: Could be abnormality in the fetus incomparable with life, mothers viral infection or other environmental factors, poor implantation, placental abnormalities, cervical insufficiency, etc. Your gynecologist is the best guide.

Usually: It is because there is something wrong with the baby. About 20% of conceptions are miscarried. Most are early. Later ones might be because there is something wrong with the cervix or placenta. Some happen without the knowledge of the woman even knowing it or that they were pregnant.

Myths ; Facts: There can be different causes at different stages, but most are not anyone's fault nor are they reasons to think it will happen again. Here is a really helpful website: http://www.Parents.Com/pregnancy/complications/miscarriage/causes-miscarriage/ congratulations ; best wishes.