What is characteristic of an inevitable abortion?

An inevitable abortion is characterized by vaginal bleeding accompanied by a dilated cervical os. This situation indicates that the pregnancy is not viable and that spontaneous abortion is impending. The presence of vaginal bleeding signifies that there is a threat to the continuation of the pregnancy, and the dilation of the cervical os reflects the body's physical response to this situation. When a cervical os is open, it suggests that the process of miscarriage is actively occurring or is very likely to occur soon.

In contrast, a closed cervical os would typically indicate that the pregnancy may still be viable and not experiencing an abortion. An open cervical os without vaginal bleeding does not accurately reflect the characteristics of an inevitable abortion, as the bleeding is a key symptom. Lastly, when products of conception are completely evacuated, it would classify the situation as a complete abortion rather than an inevitable abortion, as all products have been expelled and the threat to the pregnancy has resolved.