Do fetal electrocardiogram PR-RR changes reflect progressive asphyxia after repeated umbilical cord occlusion in fetal sheep?

The aim of this study was to determine whether there is a relationship between changes in PR-RR correlation of the fetal ECG and progressive changes in fetal acid-base status and blood pressure (BP) during repeated umbilical occlusion. Chronically instrumented fetal sheep at 126.8 ± 0.6 d (mean± SEM) were randomized to receive 1 min of total umbilical cord occlusion either every 5 min for 4 h (1:5 group; n = 8), or every 2.5 min until BP fell