Cochlear function in 1-year-old term infants born with hypoxia-ischaemia or low Apgar scores.

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 (χ(2) = 3.80-15.09, P < 0.05-0.01). Overall pass rates in the two groups were also decreased (X(2) = 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.