Outcomes of interest
In the present study, the main outcome was the final diagnosis of the EP and persistent pregnancy of unknown location. In the context of PUL, the outcome can either be: [1] ectopic pregnancy (EP), [2] failed PUL (FPUL) or [3] an intrauterine pregnancy (IUP)10. Persistent PUL (PPUL) is considered as a high-risk outcome, counted together with the outcome of ectopic pregnancy. To assess the feasibility of the tests, the secondary outcome was the expense depending on the numbers of patient’s visits and the examination.