Sensorineural Hearing Loss of Very Low Birth Weight Infants with Histological Chorioamnionitis: A Case-Control Study

Abstract

Background: Histological chorioamnionitis (HCAM) has been associated with inflammatory diseases of preterm infants. Recently, we have observed that very low birth weight infants (VLBWI) with HCAM present an increased risk of speech delay and hearing loss. So the aim of this study was to evaluate the relationship between sensorineural hearing loss (SNHL) of VLBWI and HCAM. Materials and methods: Between 2001 and 2010, we performed a double blind, case-control study on VLBWI admitted to our NICU. Each patient with HCAM was matched with one control without HCAM, of the same gestational age (plus or minus) 1 week. All infants undergo standard hearing screening before discharge by means of transient-evoked otoacustic emissions and automated auditory brainstem responses, which were repeated at 3 and 6 months of corrected age with tympanometry measurement. Incidence of SNHL at 6 months of age was compared in the two groups. The following risk factors were also studied: Apgar Score (AS) at 1 and 5 minutes, bronchopulmonary dysplasia, early and late sepsis, gentamycin and postnatal steroids administration. Results: We enrolled 204 newborns: 43 of them were excluded because of incomplete follow-up and 11 because of death. Of the remaining 150, two newborns with HCAM (2.6%) e 6 without HCAM (8.2%) presented SNHL (p = 0.16). After multivariate analysis, AS < 3 at 1 minute and administration of steroids presented an OR, respectively of 15.40 (95% CI 2.92-81.24), p = 0.001 and 8.40 (95% CI 1.40-50.47), p = 0.02. Conclusions: AS < 3 at 1 minute and administration of postnatal steroids increase the risk of SNHL in VLBWI, regardless of HCAM.