Sensorineural hearing loss and prematurity

Abstract

Objective: To elucidate clinical antecedents of sensorineural hearing loss (SNHL) in very preterm infants.

Design: Case-control study.

Subjects: Fifteen children < 33 weeks' gestation with significant SNHL born between 1 January 1990 and 31 December 1994, detected within 9 months of birth, and 30 matched control children.

Methodology: Perinatal variables in the two groups were compared using non-parametric tests and conditional logistic regression (EGRET).

Results: Median birth weight for the index group was 960 g (range 600-2914 g) compared with 1026 g (range 410-2814 g) for controls. Children with SNHL had longer periods of intubation, ventilation, oxygen treatment, and acidosis, and more frequent treatment with dopamine or frusemide. Neither peak nor trough aminoglycoside levels, nor duration of jaundice or level of bilirubin varied between groups. However, SNHL was more likely if peak bilirubin levels coexisted with netilmicin use (odds ratio (95% confidence interval) 14.2 (1.8 to 113.6)) or if acidosis occurred when bilirubin levels were over 200 micromol/l (OR 8.0 (0.9 to 71.6). Frusemide use in the face of high serum creatinine levels (OR 8.9 (1.1 to 74.5)) or netilmicin treatment (OR 5.0 (0.99 to 24.8)) was also associated with SNHL. At 12 months of age, seven of 15 children with SNHL had evidence of cerebral palsy compared with two of 30 controls (OR 12.3 (2.1 to 71)).

Conclusions: Preterm children with SNHL required more intensive care in the perinatal period and developed more neurological complications than controls. Among very preterm babies, the coexistence of risk factors for hearing loss may be more important than the individual factors themselves.