What is the most likely diagnosis for a female presenting with vaginal bleeding, mild cramping, and a dilated cervical os at 11 weeks of gestation?

The presentation of vaginal bleeding, mild cramping, and a dilated cervical os at 11 weeks of gestation is characteristic of an inevitable abortion. In this scenario, the combination of an open cervical os and the presence of vaginal bleeding indicates that the process of miscarriage has commenced and cannot be reversed. The dilation of the cervical os suggests that the pregnancy is in the process of being expelled from the uterus, which aligns with the definition of an inevitable abortion.

In cases of inevitable abortion, the passage of the pregnancy tissue has not yet occurred, but the cervical opening has begun to change, indicating that the abortion is imminent. While threatened abortion could present with similar symptoms, it typically features a closed cervical os, which rules it out in this case. Incomplete abortion refers to the expulsion of some, but not all, of the pregnancy tissue, and complete abortion means that all pregnancy tissue has been expelled, neither of which align with the symptoms of a dilated cervix at this stage. Thus, the findings presented most clearly support the diagnosis of an inevitable abortion.