Brain Ischemia

Early and reliable detection of fetal brain injury remains an unsolved challenge in fetal health monitoring. The Frasch Lab develops heart rate variability (HRV) based approaches to address this challenge.

Overview

Using fetal sheep models, we demonstrated that fetal HRV functions as a non-invasive detection tool, outperforming standard FHR monitoring for identifying asphyxia near-term. We identified why conventional monitors struggle with detecting fetal acidemia and advanced toward identifying individual cardiovascular decompensation events—critical indicators of incipient brain damage.

Key Publications

From the Frasch Lab

• Frasch et al. (2025) — Global challenges in data collection to reduce adverse perinatal outcomes, including hypoxic-ischaemic encephalopathy. BJOG
• Frasch et al. (2021) — Fetal cerebral perfusion is better than fetal acidaemia for the prediction of brain injury and might be assessable by sophisticated fetal heart rate metrics. BJOG
• Frasch et al. (2021) — Heart during acidosis: etiology and early detection of cardiac dysfunction. EClinicalMedicine
• Frasch et al. (2021) — Distance to healthy metabolic and cardiovascular dynamics from fetal heart rate scale-dependent features predicts the evolution of acidemia and cardiovascular decompensation. Frontiers in Pediatrics
• Gold, Frasch et al. (2021) — Fetal cardiovascular decompensation during labor predicted from the individual heart rate tracing: a machine learning approach in near-term fetal sheep. Frontiers in Pediatrics
• Frasch (2021) — Bezold-Jarisch reflex in the near-term fetus during labor: a matter of time (Letter to the Editor). Am J Physiol Regul Integr Comp Physiol
• Frasch et al. (2021) — Update to the dataset of cerebral ischemia in juvenile pigs with evoked potentials. Scientific Data
• Frasch et al. (2021) — Multimodal pathophysiological dataset of gradual cerebral ischemia in a cohort of juvenile pigs. Scientific Data
• Gold, Frasch et al. (2018) — Introduced stochastic change-point detection algorithms for biological signal analysis. Frontiers in Physiology
• Fetal brain injury detection via HRV — bioRxiv preprint, 2017
• Li et al. (2015) — Confirmed sampling frequency effects on pH and base excess prediction. Physiol Meas. 36(5):L1-12
• Durosier et al. (2014) — Established that sampling frequency significantly impacts acidemia detection capability. Front. Pediatr.
• Frasch et al. (2009) — "Heart rate variability analysis allows early asphyxia detection in ovine fetus." Reprod Sci. 16(5):509-17

Supporting Research from the Field

• Comparison of 5 experts and computer analysis in rule-based fetal heart rate interpretation — Parer & Hamilton, Am J Obstet Gynecol, 2010
• The 2008 NICHD Workshop Report on Electronic Fetal Monitoring: update on definitions, interpretation, and research guidelines — Macones et al., Obstet Gynecol, 2008
• Physiological time-series analysis using approximate entropy and sample entropy — Richman & Moorman, Am J Physiol Heart Circ Physiol, 2000
• PhysioBank, PhysioToolkit, and PhysioNet: components of a new research resource for complex physiologic signals — Goldberger et al., Circulation, 2000
• Heart rate variability: standards of measurement, physiological interpretation, and clinical use — Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology, European Heart Journal / Circulation, 1996
• Approximate entropy as a measure of system complexity — Pincus, Proc Natl Acad Sci USA, 1991
• Power spectrum analysis of heart rate fluctuation: a quantitative probe of beat-to-beat cardiovascular control — Akselrod et al., Science, 1981