Hearing impairment and its risk factors by newborn screening in north-western India

Assessment of Deafness in Term Infants with Birth Asphyxia with Otoacoustic Emission and Brain Stem Evoked Response Audiometry: A Prospective Observational Study

To assess deafness in term infant with birth asphyxia by otoacoustic emission and brain stem evoked response audiometry. A Prospective observational study was done at Tertiary care government hospital from 15/02/2021 to 15/10/2022.Total 130 patients were included in the study by consecutive sampling method. All the patients fulfilling the inclusion criteria during the study period were included. After explaining the aims, objectives and methods of study, written informed consent was obtained from the parents to undergo Otoacoustic Emission (OAE) and Brain Stem Evoked Response Audiometry Test (BERA). Data was entered in case record form. Collected data was analysed by appropriate statistical methods. Hearing impairment was present in eight (6.15%) asphyxiated term infants. A mild degree of hearing loss was seen in three (37.5%), a moderate degree of hearing loss was seen in four (50%), severe degree of hearing loss was seen in one (12.5%) asphyxiated term infant. In asphyxiated term infants, no significant difference in hearing loss was seen with respect to gender, Obstetrics history, and type of delivery. Significant difference in hearing loss was seen in antenatal Diabetes mellitus, hypertension, family history of SNHL and APGAR Score less than 6. Severe degree of hearing loss was seen in prolonged labour and HTN mother. Significant difference in hearing loss was seen in antenatal Diabetes mellitus, hypertension, family history of SNHL and APGAR Score less than 4 and 6 in one and five minutes respectively. Severe degree of hearing loss was seen in prolonged labour and HTN mother.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-024-04736-2.

Assessment of Hearing Impairment in Sick Newborns: A Prospective Observational Study

BACKGROUND

 Undiagnosed neonatal hearing loss causes severe language, cognitive, and behavioral problems in children. Sick newborns who spend 48 hours in the neonatal intensive care unit (NICU) have a 10- to 20-fold increased risk of permanent hearing loss. The aim of this study is to identify hearing impairment in high-risk sick newborns who spend at least 48 hours in the NICU.

METHODS

 The present prospective observational study was conducted at a single center. All sick neonates admitted to the NICU for a minimum of 48 hours at the JK Lon Hospital, Zanana Hospital, and Mahila Chikitsalaya, Sawai Man Singh (SMS) Medical College, Jaipur, Rajasthan, India, from June 2017 to May 2018 were considered eligible for the study. The primary outcome was the assessment of hearing loss of high-risk newborns using otoacoustic emissions at the time of discharge, six weeks of age, and automated auditory brainstem response (AABR) at three months of chronological age. The secondary outcome was to analyze the association of hearing loss with different risk factors in high-risk neonates.

RESULTS

 A total of 150 infants who had one or more risk factors were studied, 60 were female and 90 were male. No statistically significant difference in hearing loss was observed based on birth weight, sex, and gestational age. The first distortion-product otoacoustic emission (DPOAE) screening was done on infants at the time of discharge from the NICU. Eighty-three infants (55.33%) had "refer" on the first DPOAE and the remaining 67 (44.67%) were passed results at the time of discharge. At six weeks of life, on repeat screening with a second DPOAE test, 36% "refer" on the first screen had a "refer" result on the second DPOAE. However, 4.4% "pass" on the first screen turned out to be "refer" on the second screen. These 33 infants who had "refer" results on the second screen were subjected to testing. At 10 weeks of life, AABR was performed on 33 infants. Eleven infants out of 33 had sensorineural hearing loss (SNHL) on AABR. Hearing impairment with the DPOAE test was observed with risk factors neonatal hyperbilirubinemia (NHH), hypoxic ischemic encephalopathy (HIE), and very low birth weight (VLBW) and was statistically significant among all risk factors. But, no such association (between hearing impairment and risk factors) was observed with the AABR test. In our study, we found that the duration of mechanical ventilation in mean days 7.67±6.24 had statistically significant SNHL compared to the lesser duration of mechanical ventilation (p<0.001).

CONCLUSION

Two-stage DPOAE done prior to AABR is helpful in the early detection of hearing loss.

Role of Otoacoustic Emission Test in Early Diagnosis of Hearing Impairment in Infants

Hearing impairment is most common congenital dissorder and undiagnosed hearing loss can cause disorder in speech, language with delay in social and emotional developments. Early detection of Hearing Impairment in Infants and too access the relationship between selected risk factor and hearing loss. Neonates age upto 15 days randomly selected from pediatric and obstetrics and gynaecology department, born during this period were screened by OAE before their discharge from the hospital and after stabilizing high risk neonates. Informed consent of neonates parent/guardian was obtained before babies were subjected to OAE. A total of 400 neonates were screened for hearing loss by otoacoustic emission. Out of that 18 (4.5%) neonates failed the test in initial screening and were asked for follow up screening. Two neonates were lost to follow up. Out of 16 neonates, 2 (12.5%) neonate failed the test on follow up screening by otoacoustic emission and was referred for BERA. Neonates were classified as low and high risk basis of risk factors present. Out of 76 neonates having high risk of hearing loss, 16 failed the test. Similarly out of 324 neonates with low risk of hearing loss, only one neonate failed the test. Chi square analysis has revealed highly significant results (p < 0.001). Late identification of hearing loss presents a significant public health concern. However, without screening, children with hearing loss are usually not identified until 2 years of age, which results in significant delays in voice communication, language communication, social, cognitive, and emotional development. In contrast, early recognition, and intervention prior to 3 months of historic period has a significant positive impact on development.

Otoacoutic Emission Testing in Preterm and Term Sick Newborns: A Comparative Analysis

In newborns, both term and preterm, cochlear hearing loss is common due to different pathologies. Currently accepted methods for hearing screening in newborns are otoacoustic emission (OAE) and auditory brainstem responses. Among these two, OAE is quicker, economical and more accessible. In the present study we assessed OAEs in sick newborns, both term and preterm, having different pathological conditions. This descriptive study was conducted over 3 months in sick newborn care unit (SNCU) in a tertiary care hospital. All sick newborns admitted to SNCU in the study period were tested for otoacoustic emission. The results were subjected to the Chi square test (test of independence). Among 640 sick newborns, 184 were preterm; the rest being term newborns. Among the term sick newborns, 4.8% of those with birth asphyxia, 8.6% of those having septicaemia, 25% of those with hyperbilirubinemia needing exchange transfusion, 22.9% of those having meningitis and 33.3% of those with major congenital anomalies, had "refer" on OAE. Among preterm sick newborns, 30.8% of those with birth asphyxia, 32.5% of those having septicaemia, 75% of those with hyperbilirubinemia needing exchange transfusion, 41.7% of those having meningitis, 40% of those with major congenital anomalies and 8.7% of those with no co-morbidity had "refer" on OAE. Upon computing the p value of Chi square test performed on the results, the results were not significant (p = 0.85). Hence we didn't find any statistically significant difference between term and preterm sick newborns on OAE. The incidence of "refer" result in OAE increases with co-morbidities in both term and preterm sick newborns, somewhat more in preterm newborns. But preterm sick newborns do not seem to have an increased incidence of hearing impairment.

Ototacoustic Emissions-Based Hearing Assessment of Neonates in Tertiary Care Hospital

Hearing is a special sense needed for appropriate mental, speech and language development and academic performance. Even among normal babies, 50% of cases of hearing loss are missed out if screening protocol is not followed. In this study, we assess the hearing of all neonates born and brought to the tertiary care hospital, and also find out how many well babies with hearing loss would have been missed if this screening had not been done. Hence, the study aims to estimate the prevalence of neonatal hearing loss and study the associated risk factors. Neonates (N = 1559) attended the outpatient department of paediatrics were included. A detailed history of the neonates with special emphasis on prenatal, natal, postnatal, family history, and maternal risk factors were elicited. Three-stage hearing testing protocol was followed with transient evoked otoacoustic emission testing, a gold standard test for stage 1 and 2 and brainstem evoked response audiometry for stage 3. Of 1559 neonates, 138 had hearing loss. History of drug intake, order of the child, place of delivery and maternal history were the significant factors associated with hearing loss in neonates. Bivariate analysis revealed order of child, maternal history, and history of drug taken were the significant factors affecting the hearing loss in the neonates (P < 0.001). The prevalence of hearing loss was 8.85%. Early detection of hearing loss is essential for timely intervention and development of optimal communication skills. Further studies are required to decide the essentiality of Universal New-born hearing screening.

Role of Hearing Screening in High-Risk Newborns

Hearing is one of the very important five senses. The most important period for language and speech development is generally regarded as the first three years of life. For the past 20 years, electrophysiological methods are most commonly used which include otoacoustic emission (OAE) and auditory brain stem response (ABR). Regardless of the screening method chosen, hearing screening, though critical, is only the first stage of a comprehensive early intervention plan. Screening alone is useless unless appropriate diagnostic testing services and high quality amplification and rehabilitation services are in place and are implemented in a timely fashion. Early screening does not substitute for further periodic childhood hearing screening. To screen the newborns which are high risk or born to high risk mother using optoacoustic emission and auditory brain stem response (ABR). Also to co-relate hearing loss with various risk factors involved in pre-natal, natal and post-natal. Methods: we conducted a prospective study with 100 high risk newborns in a tertiary care centre. First, all babies were screened using transient evoked otoacoustic emission(TEOAE). Babies not responsive in this were screening again after 14 days using TEOAE. Babies who were reffered to during this screening with TEOAE were subjected to further screening with ABR to confirm the diagnosis. Out of 100 infants, 73% infants passed first screening by TEOAE whereas 27% failed. those 27 infants which failed were screened after 14 days, of them, 3 (11.1%) infants failed the second screening and were referred. Further screening with BERA was conducted for 3 children who failed the second screening by TEOAE. Of them 1 (33.3%) infant passed the BERA whereas 2 infants failed. Test of significance observed no statistically significant association of OAE with prenatal risk factors in present study (p>0.05). whereas shows highly statistically significant association of OAE with natal (birth asphyxia, NICU admission and Apgar score at 5 minutes) and post natal (viral/bacterial infections) risk factors (p<0.01). New born hearing screening is important in recognizing babies born with congenital hearing loss. The screening protocol using OAE can be used in a two staged screening. This study aimed to detect the congenital hearing loss as early as possible and its association with various risk factors in high risk newborns and role of OAE and ABR as a screening tool. Timely diagnosis and intervention for hearing loss are not the reality throughout India. The population and professionals involved in childcare should be made aware of the impact of hearing loss, this could result in better outcome of neonatal hearing screening programs.

Role of Otoacoustic Emissions in Hearing Assessment of Neonates: A Prospective Observational Study

Hearing plays an important role for children in learning speech and language, socialization and cognitive development. The child learns to speak based on what is heard (Rundjan et al. in Sari Pediatr 6(4):149-154, 2005). The aim of the study was to find out the percentage of hearing loss by OAE among low risk and high risk neonates. All the neonates (Low and High risk) born in a tertiary care center were screened by OAE before their discharge from the hospital and after stabilizing high risk neonates. The referred neonates were followed after two weeks. Total 722 neonates were screened of which 130 were high risk and 592 were low risk. Neonates with Serum bilirubin > 20 mg/dl or requiring exchange transfusion were excluded as OAE will be unreliable in them and they should be subjected to BERA directly. Percentage of bilateral hearing loss came to be 4.2%, 4 participants were lost to follow up and percentage of hearing loss on subsequent OAE came to be 11.6%. Low birth weight was an important risk factor for hearing loss (p value significant on initial and follow-up). Percentage of hearing loss with low birth weight, hyperbilirubenemia, low apgar score and prematurity to be 16%. Mechanical ventilation contributed 13% of total hearing loss followed by ototoxicity. Neonates with family history of childhood SNHL, in utero infection, craniofacial anomaly and bacterial meningitis contributed 3% of total hearing loss. On subsequent follow-up, one neonate was low-risk and the other 25 were high risk, of which 3 high risks showed sustained OAE refer. However the low risk neonate had normal outer hair cell function i.e. OAE pass. This study clearly demonstrates importance of Universal Neonatal Hearing Screening Programme so that hearing loss can be detected as early as possible and possible intervention can be taken at the earliest.

Screening of Newborn Hearing at a Tertiary Care Hospital in South India

Hearing loss can have a devastating impact on the cognitive development and psychological well-being of children and their families. Newborn hearing screening should be given special attention especially in a country like ours where the burden of this disability is heavy. Screening all newborns irrespective of risk factors helps in better detection, and hence further management can be initiated at appropriate time. To implement newborn hearing screening at Vanivilas hospital and to estimate the incidence of hearing loss among the high risk groups. To create awareness about the need for detecting childhood deafness among parents and general population. To develop a centre of excellence for evaluation, intervention and rehabilitation for hearing impaired in a tertiary care hospital. Prospective study. All neonates born in Vanivilas Hospital attached to Bangalore Medical College and Research Institute underwent hearing screening using four stage protocols with otoacoustic emission (OAE) tests and final confirmation with Brainstem evoked response audiometry (BERA) tests. May 2015-May 2017. Number of newborns screened were 26,487, and 19 (0.717/1000) newborns were detected to have hearing impairment. The incidence of hearing loss among high risk group was 0.188/1000, and among the non risk group was 0.528/1000. Newborn hearing screening must be made mandatory and multi-staged protocol based screening for hearing loss should be implemented. This will make newborn screening programme more efficient and also will help in initiating treatment at an early stage so that further damage can be prevented.