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Title: Neonatal antecedents of hearing loss in very preterm infants
Author: Chant, K. C.
ISNI:       0000 0004 7227 6743
Awarding Body: UCL (University College London)
Current Institution: University College London (University of London)
Date of Award: 2017
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BACKGROUND: The prevalence of hearing impairment in infants born prematurely or with low birth weight is around 1-2%, up to 10 times higher than babies born at term. The aetiology of which is poorly understood; risk factors are likely to be interrelated. Susceptibility to the audiological toxicity of gentamicin, frequently given to newborn babies, is increased in the presence of m.1555A > G, a mitochondrial mutation. OBJECTIVES: This study aims to investigate the aetiology of hearing loss in infants following neonatal intensive care, and the burden that m.1555A > G represents to deafness in children born at less than 32 weeks gestational age. METHOD: This was a case control study of preterm children with hearing loss in Greater London. Controls (up to 5 per case) had normal hearing and were matched for sex, gestational age and hospital in which they received neonatal care. Saliva samples were taken from all children for genetic screening of m.1555A > G. Audiological, pharmacological and clinical data were abstracted from medical notes. RESULTS: Two hundred and thirty seven children, 57 children with hearing loss, were recruited to the study. Independent risks included low gestational age, low birthweight, patent ductus arteriosus, acquired brain injury, the use of inotrope, steroid, vancomycin, furosemide, elevated bilirubin and creatinine levels. Cumulative doses of gentamicin, vancomycin, and furosemide also increased the risk of impaired hearing. One child with normal hearing had the m.1555A > G mutation and had been exposed to aminoglycosides. A high frequency hearing loss has since been detected. DISCUSSION: The prevalence of m.1555A > G was 0.41%, and is unlikely to explain the increased rate of hearing loss in preterm infants. Children with hearing loss were exposed to a greater number of interacting risk factors across a timeline of care. Cumulative ototoxic medication in particular, increased the likelihood of hearing loss, warranting closer monitoring throughout neonatal care.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available