Postnatal Laboratory Timers of Antenatal Hypoxemic–Ischemic Brain Damage

OBJECTIVE: Markers were sought to identify the antenatal starting times and rates at which brain damage advanced in children with hypoxemic–ischemic cerebral palsy. STUDY DESIGN: Fetal bradycardia's onset marked the damage's start. Using this baseline, the following were tested as additional timers of the damage's onset: serial blood counts of neonates’ normoblasts, platelets, lymphocytes, differences at birth between base excess values in umbilical arterial and venous bloods, brain damage patterns. RESULTS: Each timer had a broad antenatal time frame within which it could identify specific damage starting times. The broad time frames are as follows: Blood lymphocyte counts: 0.45 to 13.8 hours before birth, blood normoblast counts: 0.45 to 55.0 hours before birth, blood platelet counts: 0.5 to >72 hours before birth. Brain damage patterns: 0.4 to >0.7 hour before birth. Hyperventilating and hyperoxygenating neonates greatly accelerated the damage's advance. CONCLUSIONS: Commonly obtained laboratory values and brain images can identify when such brain damage began and the rate at which it advanced.