Prevalence of hearing impairment in neonatal encephalopathy due to hypoxia-ischemia: a systematic review and meta-analysis

Background: This systematic review was undertaken to estimate the overall prevalence of hearing impairment in survivors of neonatal HIE. Methods: PubMed, EMBASE, CINAHL, EMCARE and Cochrane databases, mednar (gray literature) were searched till January 2023. Randomized controlled trials and observational studies were included. The main outcome was estimation of overall prevalence of hearing impairment in survivors of HIE. Results: A total of 71studies (5821 infants assessed for hearing impairment) were included of which 56 were from high income countries (HIC) and 15 from low- or middle-income countries (LMIC). Overall prevalence rate of hearing impairment in cooled infants was 5% (95% CI: 3–6%, n = 4868) and 3% (95% CI: 1–6%, n = 953) in non-cooled HIE infants. The prevalence rate in cooled HIE infants in LMICs was 7% (95% CI: 2–15%) and in HICs was 4% (95% CI: 3–5%). The prevalence rate in non-cooled HIE infants in LMICs was 8% (95% CI: 2–17%) and HICs was 2% (95% CI: 0–4%). Conclusions: These results would be useful for counseling parents, and in acting as benchmark when comparing institutional data, and while monitoring future RCTs testing new interventions in HIE. There is a need for more data from LMICs and standardization of reporting hearing impairment. Impact: The overall prevalence rate of hearing impairment in cooled infants with HIE was 5% (95% CI: 3–6%) and 3% (95% CI: 1–6%) in the non-cooled infants. The prevalence rate in cooled HIE infants in LMICs was 7% (95% CI: 2–15%) and in HICs was 4% (95% CI: 3–5%). The prevalence rate in non-cooled HIE infants in LMICs was 8% (95% CI: 2–17%) and HICs was 2% (95% CI: 0–4%). These results would be useful for counseling parents, and in acting as benchmark when comparing institutional data, and while monitoring future RCTs testing new interventions in HIE.