Cumulative risk factors contributing to hearing loss in preterm infants

Objective To investigate individual and concomitant risk factors for hearing loss during neonatal care. Design Case-control study. Setting Community. Population 237 children born <32 weeks of gestation; 57 with hearing loss and 180 with normal hearing born between 2009 and 2013, matched for sex, gestation and year of birth. Main outcome measures Data were abstracted from clinical records for overall risk factors daily for the first 14 days and then weekly until discharge from neonatal care. All infants were screened for the presence of m.1555A>G mutation. Results Children with hearing loss had lower birth weight for gestational age, more severe neonatal illness, with increased exposure to inotrope, steroid, gentamicin, vancomycin and furosemide, and more frequent physiological risk, elevated bilirubin and creatinine levels and acidosis, but no index child was found to have the m.1555A>G mutation, compared with one among controls. The duration of gentamicin, vancomycin or furosemide administration in the first 14 days was associated with impaired hearing (OR per dose: 1.25; 95% CI 1.14 to 1.38). Multivariate analyses revealed independent risks for hearing loss for each day when there was physiological risk (OR per day 1.15 (1.05 to 1.27)) and each day of medication exposure (OR 1.23 (1.1 to 1.37)). Conclusion Although the relative contribution of underlying illness and medication cannot be identified by this study, cumulative use of ototoxic medication and the presence of physiologic risk factors independently increased the likelihood of hearing loss, warranting close monitoring of coincident therapy throughout neonatal critical care.