Pregnancy of Unknown Location

Pregnancy of unknown location (PUL) is a non-diagnostic classification term that arises when a patient has a positive urinary pregnancy test, but a pregnancy cannot be visualised on a transvaginal ultrasound scan. The management of patients classified with a PUL is often variable. It should however be dictated by triaging women into either at low-risk or high-risk of complications. Various management protocols exist to triage PUL including: 1. a single hCG and progesterone level, 2. hCG ratio (hCG at 48 hours / hCG at 0 hours) and 3. risk prediction models utilising hCG and progesterone levels.