Risk factors for sensorineural hearing loss in extremely premature infants

Objective: To identify potentially preventable risk factors for sensorineural hearing loss (SNHL) in extremely premature infants.
Methodology A case control study of survivors with gestational age (GA) <28 weeks or birthweight (BW) <1000 g using data collected prospectively in our Neonatal Intensive Care Unit database. Each subject with bilateral SNHL >40dB was matched according to GA, BW and sex with two controls who had neither sensorineural nor conductive hearing loss.
Results Infants with SNHL had increased mean (±s.d.) days ventilated (53 ± 21 vs 37±23 days, P = 0.006) and in oxygen (107±44 vs 69±28 days, P = 0.02) compared with controls. The risk for SNHL was increased for infants who spent >90 days in oxygen (OR 4.0 [95% Cl 1.1-15.6]), had maximum FiO₂ >0.90 (5.6 [1.2-26.9]), minimum plasma Na <125mmol/L (5.6 [1.1-27.8] or maximum pH >7.60 (5.6 [1.1-89.0]). Neither maximum serum bilirubin nor exposure to ototoxic drugs was associated with SNHL.
Conclusions: Avoidance of severe hyponatraemia and extreme alkalosis, as well as use of surfactant to minimize the severity of hyaline membrane disease, may result in a decreased incidence of SNHL in extremely premature infants.