OBJECTIVE:To assess the cost-effectiveness of the use of cardiotocography (CTG) complemented with fetal electrocardiography and ST analysiscompared with the use of CTG alone in term deliveries when a decision has been made to use fetal monitoring with a scalp electrode. DESIGN:A cost-effectiveness analysis based on a probabilistic decision model incorporating relevant strategies and lifelong outcomes. SETTING:Maternity wards in Sweden. POPULATION:Women with term fetuses after a clinical decision had been made to apply a fetal scalp electrode for internal CTG. METHODS:A decision model was used to compare the costs and effects of two different treatment strategies. Baseline estimates were derived from the literature. Discounted costs and quality-adjusted life years (QALYs) were simulated over a lifetime horizon using a probabilistic model. MAIN OUTCOME MEASURES:QALYs, incremental costs, and cost per QALY gained expressed as incremental cost-effectiveness ratio (ICER). RESULTS:The analysis found an incremental effect of 0.005 QALYs for ST analysis compared with CTG; the ST analysis strategy was also moreover associated with a euro56 decrease in costs, thus dominating the CTG strategy. The probability that ST analysis is cost-effective incomparison with CTG is high, irrespective of the willingness-to-pay value for a QALY. CONCLUSIONS:Compared with CTG alone, ST analysis is cost-effective when used in term high-risk deliveries in which there is a need for internalfetal monitoring.