Summary: A miscarriage is an unexpected loss of pregnancy before the 20th week of pregnancy. Most miscarriages happen very early in the pregnancy, often before a woman even knows she is pregnant.Factors that may contribute to miscarriage include : a genetic problem with the fetus, problems with the uterus or cervix,chronic diseases, such as polycystic ovary syndrome. Signs of a miscarriage include vaginal spotting, abdominal pain or cramping, and fluid or tissue passing from the vagina. Bleeding can be a symptom of miscarriage, but many women also have it in early pregnancy and don't miscarry. To be sure, contact your health care provider right away if you have bleeding. More >> Less >>

Reference Material:
https://medlineplus.gov/miscarriage.html