['The purpose of our study was to examine the neuronal outcome after a standardized period of umbilical cord occlusion.', 'The umbilical cord was clamped for 10 minutes in nine experimental and four control chronically instrumented fetal sheep. Three days later the animals were killed for histologic interpretation. Systemic, electrophysiologic, and neurohistologic effects were compared by analysis of variance.', 'Clamping of the cord resulted in transient severe asphyxia, hypotension (24 +/- 5 mm Hg, p < 0.01), bradycardia (72 +/- 14 beats/min, p < 0.001), depressed electroencephalographic activity (-17 +/- 2 dB, p < 0.001), and an increase in cortical impedance. The electroencephalographic activity was depressed for 5 +/- 2 hours in spite of rapid recovery of arterial oxygen content. Neuronal loss was found in the hippocampus. Neither epileptiform electroencephalographic activity nor infarction were observed. Three animals with poor blood gas levels died during the occlusion.'] Does transient umbilical cord occlusion cause hippocampal damage in the fetal sheep?