A missed abortion refers to a situation where the fetus dies in the uterus but is not expelled. This condition is also known as a silent miscarriage. The woman may not experience the typical symptoms of miscarriage, such as bleeding or cramping, and the diagnosis is often made during a routine ultrasound when no fetal heartbeat is detected. Complete abortion involves the complete expulsion of fetal tissue, inevitable abortion is when the miscarriage cannot be stopped, and threatened abortion refers to any bleeding in the first 20 weeks of pregnancy without cervical dilation.