Does Maturity Affect Cephalic Perfusion and T/QRS Ratio during Prolonged Umbilical Cord Occlusion in Fetal Sheep?
Figure 4
The relationship between changes in mean arterial pressure (MAP, % baseline) and T/QRS ratio in 0.6 gestation (0.6 GA), 0.7 gestation (0.7 GA), and 0.8 gestation (0.8 GA) fetuses. (a) shows the within-subjects relationship changes from the start of occlusion until the peak T/QRS ratio; the period when most important fetal cardiovascular adaptations take place (0.6 GA: N.S., ; 0.7 GA: N.S., ; 0.8 GA: , , ). (b) shows the within-subjects relationship changes from the peak T/QRS ratio until 15 minutes of occlusion; the period during which most of the fetal decompensation occurs (, , ). There was no significant effect of gestational age. Different symbols represent individual animals, while the dotted lines indicate the within-subject regression relationship. Seven of 25 fetuses did not have a positive relationship between MAP and T/QRS ratio during the early phase of occlusion.
