SonoSim Ultrasound Challenge: OB/GYN

This 25-year-old female with a previously documented eight-week intrauterine pregnancy presents with vaginal bleeding, lower abdominal pain, and passage of tissue. Using ultrasound, what is the most likely diagnosis?

Findings: Retained products of conception and intrauterine blood clots; Trace free fluid in posterior cul-de-sac; Incomplete miscarriage