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Updated: Feb 14, 2026

Evaluation of Cerebral Blood Flow Autoregulation in the Rat Using Laser Doppler Flowmetry
Published on: January 19, 2020
Utility of prenatal Doppler ultrasound to predict neonatal impaired cerebral autoregulation
Sruthi R Polavarapu1, Garrett D Fitzgerald2, Stephen Contag2
1Pediatrics, University of Maryland, Baltimore, MD, USA. Sruthi.R.Polavarapu@drexel.edu.
Objective:
Determine if abnormal prenatal Doppler ultrasound indices are predictive of postnatal impaired cerebral autoregulation.
Study Design:
Prospective cohort study of 46 subjects, 240-296 weeks' gestation. Utilizing near-infrared spectroscopy and receiver-operating characteristic analysis, impaired cerebral autoregulation was defined as >16.5% time spent in a dysregulated state within 96 h of life. Normal and abnormal Doppler indices were compared for perinatal outcomes.
Results:
Subjects with abnormal cerebroplacental ratio (n = 12) and abnormal umbilical artery pulsatility index (n = 13) were likely to develop postnatal impaired cerebral autoregulation (p ≤ 0.02). Abnormal cerebroplacental ratio was associated with impaired cerebral autoregulation between 24 and 48 h of life (p = 0.016). These subjects have increased risk for fetal growth restriction, lower birth weight, lower Apgar scores, acidosis, and severe intraventricular hemorrhage and/or death (p < 0.05).
Conclusion:
Abnormal cerebroplacental ratio and umbilical artery pulsatility index are associated with postnatal impairment in cerebral autoregulation and adverse outcome.
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