OC01.04: A multicentre trial on the performance of a two‐step triage protocol based on initial serum progesterone and serial hCG used to manage pregnancies of unknown location (PUL).

OC01.04: A multicentre trial on the performance of a two-step triage protocol based on initial serum progesterone and serial hCG used to manage pregnancies of unknown location (PUL) We previously published a two-step triage protocol based on the presenting serum progesterone (step 1) and M6 model, a logistic regression model based on the initial hCG and hCG ratio two days later (step 2) to select PUL at high-risk of ectopic pregnancy (EP). In seven centres, if the progesterone was <=2nmol/l, patients were discharged with a follow-up urine pregnancy test in two weeks to confirm a negative result. [Extracted from the article]