Brainstem auditory evoked response at term in preterm infants after perinatal hypoxia-ischaemia

Aim: To examine brainstem auditory function in preterm infants after perinatal hypoxia-ischaemia (HI). Methods: Brainstem auditory evoked response (BAER) was studied at 37-42 wk postconceptional age in preterm infants who suffered perinatal HI, and were compared with those in preterm and term infants without any major perinatal problems. Results: None of the latencies of waves I, III and V in the BAER in preterm infants after perinatal HI differed significantly from those in preterm and term controls. There were also no significant differences in the I-V and I-III interpeak intervals between preterm infants after HI and the controls. However, III-V interval in infants after HI tended to increase, and was significantly longer than in term controls (p < 0.01) although it did not differ significantly from that in preterm controls. Similarly, the III-V/I-III interval ratio was greater than in term controls (p < 0.05), but was similar to that in preterm controls. All amplitude variables did not differ significantly from the controls. Conclusion: BAER in preterm infants after perinatal HI did not differ significantly from that in preterm infants without perinatal problems, but differed slightly from that in normal term infants. The prolonged III-V interval as compared with the term controls suggests a minor impairment in central auditory function.