Bleeding in early pregnancy

1. Big picture

Bleeding in early pregnancy means vaginal bleeding in a woman with a positive pregnancy test before fetal viability, usually in the first trimester and classically before 12 weeks.

The examiner wants you to think in this order:

Positive pregnancy test + bleeding
        ↓
Is the mother unstable?
        ↓
Could this be ectopic pregnancy?
        ↓
Is the pregnancy intrauterine and viable?
        ↓
Is this miscarriage, molar pregnancy, or non-pregnancy genital tract bleeding?

The key exam message is: do not diagnose miscarriage until ectopic pregnancy has been excluded.