OBJECTIVE Functional status of the brainstem auditory pathway was examined at four months of corrected postnatal age in infants born below 30 week gestation to assess the effect of very or extremely preterm birth on postnatal development of the pathway. METHODS Thirty-four preterm infants born at 24-29 week gestation (GA24-29w) were studied at four months of corrected postnatal age. Normal controls were 38 postnatal age-matched term infants. Maximum length sequence brainstem auditory evoked response (MLS BAER) were recorded and analysed with 60 dB nHL clicks. RESULTS Compared with term control group, GA24-29w group manifested higher BAER threshold (p < 0.05), longer MLS BAER wave latencies at all click rates 91-910/s (p < 0.01-0.001), and lower wave amplitudes at most click rates (p < 0.05-0.01). No significant differences were found between the two groups in I-V interval at any click rates. I-III interval was shorter while III-V interval was longer in GA24-29w group than in term group at higher rates (all p < 0.05). III-V/I-III interval ratio in GA24-29w group was greater at 455 and 910/s clicks (p < 0.05 and 0.01). These interval variables showed similar changes when 4 GA24-29w infants with threshold elevation were excluded. CONCLUSIONS At four months of corrected postnatal age, infants born below 30 week gestation manifested elevated BAER threshold, increased wave latencies, and reduced amplitude. They also manifested a small decrease in I-III interval but a small increase in III-V interval at high rates. Very or extremely preterm birth exerts a mild or moderate effect on postnatal development of the brainstem auditory pathway.

中文翻译：

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妊娠 30 周以下早产儿纠正出生后四个月时的脑干听觉通路功能

目的 在 30 周以下出生的婴儿的校正出生后四个月时检查脑干听觉通路的功能状态，以评估极早产或极早产对该通路的出生后发育的影响。方法 对 34 名 24-29 周出生的早产儿 (GA24-29w) 进行了研究，这些早产儿的校正出生后年龄为 4 个月。正常对照是 38 名出生后年龄匹配的足月婴儿。最大长度序列脑干听觉诱发反应 (MLS BAER) 用 60 dB nHL 点击记录和分析。结果 与足月对照组相比，GA24-29w组表现出更高的BAER阈值（p < 0.05），在所有点击率91-910 / s（p < 0.01-0.001）下更长的MLS BAER波延迟，以及在大多数点击时较低的波幅率（p < 0.05-0.01）。在任何点击率下，两组在 IV 间隔中均未发现显着差异。与足月组相比，GA24-29w 组的 I-III 间期更短，而 III-V 间期更长（所有 p < 0.05）。GA24-29w 组的 III-V/I-III 间隔比在 455 次和 910 次点击时更高（p < 0.05 和 0.01）。当排除 4 名阈值升高的 GA24-29w 婴儿时，这些区间变量显示出类似的变化。结论 在出生后 4 个月的校正年龄时，小于 30 周出生的婴儿表现出 BAER 阈值升高、波潜伏期增加和振幅降低。他们还表现出 I-III 间期的小幅下降，但在高速率下 III-V 间期的小幅增加。极早产或极早产对脑干听觉通路的出生后发育产生轻度或中度影响。