Inevitable miscarriage refers to the presence of an open internal os in the presence of bleeding in the first trimester of pregnancy. Most often intra cervical contents are present at the time of examination.
Essentially, a threatened miscarriage progresses to an inevitable miscarriage if cervical dilatation occurs. Once tissue has passed through the cervical os, this will then be termed an incomplete miscarriage and ultimately a complete miscarriage.
Cervical ectopic pregnancy is a rare but potentially catastrophic differential that should be excluded by means of a repeat ultrasound and serial beta HCG. If cervical ectopic is not considered as a differential for a gestational sac in the endocervix, curretage of a presumed incomplete miscarriage may result in unexpected severe hemorrhage.