MAPT and perinatal asphyxia: Furthermore, serum tau and S100B levels in the III°AFC-HIE group were significantly higher than in the NAF-HIE and I°AFC-HIE groups, which is likely related to the higher incidence of severe HIE cases in the III°AFC-HIE group, and the higher incidence of moderate HIE cases in the NAF-HIE and I°AFC-HIE groups; therefore, the higher the AFC level, the more serious the neonatal brain damage.