Activity-based costing in the management of pregnancy of unknown Location: Comparing current practice in Denmark with the M6NP model, and the NICE guidelines

Introduction Pregnancy of unknown location (PUL) is defined by elevated serum human chorionic gonadotrophin (s-hCG) and no detectable pregnancy on transvaginal ultrasound (TVUS). The main concern is ectopic pregnancy (EP), which occurs in 5–20% of PUL cases. Risk stratification models such as M6NP and NICE aim to identify high-risk PUL cases while reducing unnecessary follow-up for low-risk cases. Their cost-effectiveness in Danish healthcare setting and costs of current clinical management, are unknown.MethodsThis secondary analysis used data from a two-centre retrospective cohort study of 725 women with PUL managed at two Danish university hospitals. Risk stratification was retrospectively applied using the M6NP model and NICE guidelines. The cost analysis was conducted from a hospital perspective using actual costs based on current management. Theoretical costs were based on recommended follow-up for each risk category as defined by the models. Sensitivity analyses varied unit costs, and differences were compared using the Wilcoxon signed-rank test.ResultsThe actual total cost for diagnosing 725 women with PUL was €224,159 averaging €309 per woman and €3,449 per EP. Applying the M6NP model reduced costs by 10% (€32 per woman), while the NICE guidelines reduced costs by 12% (€38 per woman) compared to current practice. NICE resulted in the lowest total costs. Sensitivity analyses confirmed these findings across all cost scenarios.ConclusionImplementation of the M6NP model or NICE guidelines would result in up to 10–12% theoretical cost reduction compared with current practice; patient safety must remain a key consideration in PUL management.