Perinatal asphyxia with no or mild hypoxic-ischaemic encephalopathy: Two-year neurodevelopmental outcome

To characterize 2-year neurodevelopment of infants with perinatal asphyxia without hypoxic-ischemic encephalopathy (HIE) or with mild HIE (HIE1) and analyse possible correlations with sex, brain MRI findings or early neurological examination.

Term infants with perinatal asphyxia and a control group were prospectively recruited from the neonatal units of Helsinki University Hospital in 2016-2020. The study cohort included infants with no or minor neurological symptoms during first 6 h after birth. Neurodevelopment was assessed using Hammersmith Infant Neurological Examination (HINE) at three months and at two years, Griffiths Scales of Child Development, 3rd edition (GMDS-III) and Bayley Scales of Infant and Toddler Development, 3rd Edition (BSID-III) at two years.

Study included 89 infants: 32 study cohort infants and 57 healthy controls. In the study cohort 1/32 and in the control group 0/57 of the infants showed significantly below normative mean cognitive score in BSID-III. Respective frequency of significantly below normative mean receptive language score were 2/32 and 0/57 and expressive language score 4/32 and 8/57. Females with perinatal asphyxia performed better in the language scores of GMDS-III and BSID-III. Children with asphyxia-related findings in brain MRI had statistically significantly lower total score, language and communication and foundations of learning subscore of GMDS-III.

Most infants with perinatal asphyxia without HIE or with HIE1 performed typically at two years. However, infants with asphyxia-related MRI findings showed lower cognitive and language scores. Our results suggest that female sex may be associated with a lower risk of any subtle effects.