Adjunctive technologies to electronic fetal monitoring: Promise, pitfalls, and lessons learned

Despite widespread use, electronic fetal monitoring (EFM) has not demonstrably reduced perinatal morbidity or mortality, and likely contributed to the rise in cesarean delivery. To improve its utility, a number of adjunctive approaches have been introduced over the past three decades, including fetal pulse oximetry, ST segment analysis (STAN), and maternal oxygen supplementation. Each intervention was supported by strong physiologic rationale, yet none achieved widespread clinical adoption due to inconsistent evidence of benefit and, in some cases, potential harm. This review critically evaluates landmark studies on EFM adjuncts, highlights the limitations that have impeded progress, and outlines emerging innovations, including artificial intelligence and multimodal surveillance. The persistent challenges in intrapartum fetal assessment underscore the need for high-quality evidence, rigorous implementation strategies, and a patient-centered reframing of EFM goals.