• hearing impairment;
  • hypoxia;
  • neonatology;
  • otoacoustic emissions

Aim:  To examine the influence of perinatal hypoxia-ischaemia (HI) or low Apgar scores on distortion product otoacoustic emissions (DPOAEs) in infants at 1 year and detect any postnatal changes.

Methods:  Eighty-eight term infants born with perinatal HI or low Apgar scores alone were recruited at 1 year of age. The ears with type A tympanogram (normal) were studied with DPOAEs at 10 frequencies between 0.5 kHz and 10 kHz.

Results:  DPOAE pass rates were decreased at all frequencies 1–10 kHz, particularly 1 and 2 kHz in both infants born with HI and those with low Apgar scores (χ2= 3.80–15.09, P < 0.05–0.01). Overall pass rates in the two groups were also decreased (X2= 10.78 and 12.12, P < 0.01 and 0.01). No marked differences were found between infants born with HI and those with low Apgar score. Compared with those recorded at 1 and 6 months, DPOAE pass rates at 1 year were increased slightly in infants born with HI, but showed no marked changes in those born with low Apgar scores.

Conclusions:  DPOAE pass rates, mainly at 1 and 2 kHz, were decreased at 1 year in infants born with perinatal HI and low Apgar scores, suggesting a relative poor cochlear function. Further studies are needed to ascertain the hearing acuity.