Abortion, spontaneous

A miscarriage is the spontaneous loss of pregnancy from conception to 20 weeks gestation. The term stillbirth refers to the death of a fetus after 20 weeks of gestation. Miscarriage is sometimes referred to as spontaneous abortion because the medical term abortion means ending a pregnancy, whether intentional or unintentional. Most miscarriages occur in the first trimester of pregnancy, from seven to twelve weeks after conception.