title: Sex and gestational age effects on auditory brainstem responses in preterm and term infants.
abstract: BACKGROUND
  Some studies find delayed development of the auditory brainstem in preterm infants, but others do not.
  
  
  OBJECTIVE
  To compare auditory brainstem responses (ABRs) in healthy preterm and term infants depending on sex and gestational age (GA).
  
  
  METHODS
  Participants were 111 preterm (27-36weeks GA) and 92 term (37-41weeks GA) infants. ABR tests were conducted at 6weeks (corrected age if preterm).
  
  
  RESULTS
  There were no overall differences between term and preterm groups in ABRs. However, males showed longer latencies for waves III, V, and I-III, III-V, and I-V intervals and smaller amplitudes for wave III and V than females in both preterm and term groups (all p values≤.01). A 3-way interaction between group, sex, and GA (p<.05) showed that preterm males with later GA had longer wave I-V interval, whereas term females with later GA showed shorter wave I-V interval. Growth velocity predicted wave I-V interval in preterm infants, controlling for other factors (male: p=.07, female: p<.05).
  
  
  CONCLUSIONS
  ABRs in preterm and term infants were similar at 6weeks (corrected age if preterm), but males had less advanced ABRs than females. More rapid growth predicted less mature ABR in later GA preterm infants in this setting where they were unlikely to receive extra iron. The roles of GA, growth, and iron balance in ABR development warrant further study.
authors: Children's Hospital Zhejiang University School of Medicine, China.
authors: Mingyan
authors: M
authors: Li
authors: Li
authors: L
authors: Zhu
authors: Xiaoqin
authors: X
authors: Mai
authors: Jie
authors: J
authors: Shao
authors: Betsy
authors: B
authors: Lozoff
authors: Zhengyan
authors: Z
authors: Zhao
mesh_terms: D001306:Auditory Pathways; D001933:Brain Stem / Q000502:physiology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D012737:Sex Factors