Hearing loss is one of the most common congenital anomalies, occurring in approximately two to four infants per 1000. Children whose hearing loss is identified, and who receive appropriate intervention before 6 months of age, develop significantly better language ability than those who are identified later.
To assess the failure rate of neonatal hearing screening in a high-risk register group of neonates and the relative importance of these risk factors in hearing impairment in the neonatal ICU (NICU) of the El-Mounira Children Hospital and identify the incidence of hearing loss.
Patients and methods
The study was carried out on 100 neonates in El-Mounira Children Hospital (NICU) and on 30 control neonates (15 boys and 15girls) chosen from Kasr El-Eini Maternity Hospital. All control cases aged 1–4 days had normal birth weight (2000–4000 g) and gestational age (35–40 weeks) and were delivered normally or by cesarean section without complications. The children in the study group were 3–23 days old (53 boys and 47 girls) and had birth weight ranging from 900 to 4000 g and gestational age ranging from 28 to 41 weeks. All the cases were screened for hearing loss using the transient evoked otoacoustic emission device (Echo-Screen), followed by a second-stage screening for those who failed the test with the transient evoked otoacoustic emission device. Those cases given a Refer were then made to undergo an Automated Auditory Brainstem Response test after 3–4 weeks.
In the NICU group, 55% had hyperbilirubinemia, requiring exchange transfusion, 13% were of low birth weight (<1500 g), and 13% were on mechanical ventilation. Other risk factors such as cranio-facial anomalies showed a combined effect. In the first screening phase, 71% were given a Pass response and 29% were given a Refer response. In the second screening phase, 28% were given a Pass, 31% were given a Refer, and 41% were dropouts, as they had passed their critical stage and had been discharged. The highest referral rates were in neonates with multiple risk factors.
A comprehensive intervention and management program must be an integral part of the screening program in the postnatal period. Public awareness about the value of hearing screening is important for follow-up to be more effective. Monitoring of ototoxic drug administration and further assessment of the high prevalence of hyperbilirubinemia are needed. A team of obstetricians, pediatricians, and audiologists is needed to identify and assess risk factors.