Glucocorticoids and Preterm Hypoxic-Ischemic Brain Injury: The Good and the Bad
Figure 1
Time sequence of changes in mean arterial pressure (MAP), fetal heart rate (FHR), carotid blood flow (CaBF), and carotid vascular resistance (CaVR) in 0.7 gestation fetuses after two maternal intramuscular injections of either saline (open squares, ) or dexamethasone (filled squares, ). Dexamethasone induced a significant increase in MAP after each injection, and pressure was elevated for 50 hours. FHR fell acutely after each injection, and there was a sustained period of tachycardia after the second injection. There was a tendency for CaBF to fall initially, and this was associated with a significant rise in resistance. However, overall there were no marked differences in cerebral perfusion and resistance. Data are shown from six hours before the first injection to 120 hours afterwards. The dashed arrows show the timing of injections. Data are one hour averages, mean (SEM), *.
