Table 1 HIE neurological and biological inclusion criteria for the LyTONEPAL cohort

Neurological signs

• Moderate HIE: lethargy, hyper-reflexia, myosis, bradycardia, seizures, hypotonia with weak suck and poor Moro reflex

• Severe HIE: stupor, flaccidity, small to mid-position pupils that react poorly to light, decreased stretch reflexes, hypothermia or absent Moro reflex

Biological criteria indicating asphyxia during the first hour after birth in a sample of umbilical-cord blood or any other blood sampled

• Severe biological signs: pH ≤7.0 or less or a base deficit ≥16 mmol per liter

• Moderate/absent biological signs with additional perinatal events:

  ○ 7.0 < pH ≤ 7.15, or 10 ≤ a base deficit < 16 mmol per liter, or blood gas measurement unavailable

  ○ With:

   - an acute perinatal event (e.g. late or variable decelerations, cord prolapse, cord rupture, uterine rupture, maternal trauma, hemorrhage, or cardiorespiratory arrest)

   - or an abrupt change in fetal heart rate (FHR), defined as a persistent abnormal FHR after a period of normal tracing: bradycardia or prolonged deceleration, persistent variable decelerations, persistent late decelerations, and reduced heart variability

   - or either a 10-min Apgar score of 5 or less or assisted ventilation initiated at birth and continued for at least 10 min.