Sensorineural Hearing Loss in Newborns Hospitalized in Neonatal Intensive Care Unit: An Observational Study

Automated ABR screening for hearing loss and its clinical determinants among newborns with hyperbilirubinemia in National Hospital, Abuja, Nigeria

Background

Severe neonatal hyperbilirubinemia is a known risk factor for sensorineural hearing loss which is usually undiagnosed in our environment until school age due to a lack of routine screening programs.

Materials and Methods

This cross-sectional study conducted between August 2020 and February 2021 employed a universal sampling of consecutive eligible participants after their mothers' consent. Hearing screening was conducted using an automated auditory brainstem response (AABR) device (Otoport OAE + ABR®). The proportion of AABR screening failure was assessed while associated clinical risk factors were determined using logistic regression. Statistical significance was set at 5% for all comparative analyses.

Results

One hundred and sixty newborns below 28 days of age, delivered at 34 weeks gestation and above, who had jaundice were recruited. The prevalence of screening AABR failure in at least one ear was 26.2%. Significant risk factors for AABR screening failure in addition to extreme and hazardous hyperbilirubinemia were acute bilirubin encephalopathy (ABE) (Odds Ratio (OR) =4.44, 95% CI = 3.19-6.17), birth weight below 2500 g (OR = 3.16, 95% CI = 1.48-6.77), dull tympanic membrane (TM) (OR = 5.94, 95% CI = 2.36-14.92) and exchange blood transfusion (OR = 4.84, 95% CI = 1.87-12.58).

Conclusion and Recommendations

The prevalence of AABR screening failure was high, and a dull TM was its strongest predictor among late preterm and term neonates with hyperbilirubinemia. Otoscopy should be included in the care of newborn with hyperbilirubinemia and screening programs established to mitigate hearing loss among high-risk neonates in Abuja.

Hearing loss in neonates and infants

Hearing in neonates and infants is crucial for their development of language and communication skills. Unless hearing loss is appropriately managed early, it can cause a significant socioeconomic burden considering its detrimental impact on the child's development and its common nature. It is also the most common congenital sensory deficit, with an approximate incidence of 1.5 per 1,000 newborns. Its etiologies are heterogeneous: genetic causes are reportedly involved in up to 80% of cases, while congenital cytomegalovirus infection is the leading environmental factor contributing to congenital hearing loss. The introduction of newborn hearing screening using automated auditory brainstem response and/or automated otoacoustic emission in many developed countries has helped detect and manage hearing loss early. Current auditory rehabilitation options such as cochlear implantation implementing cutting-edge technologies can treat almost all degrees of hearing loss, emphasizing the importance of early hearing detection and intervention. Rapidly developing genetic diagnostic technologies and future cutting-edge treatment options, including gene therapy, will shed light on the future management of hearing loss in neonates and infants.

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.

Reduced BDNF expression in the auditory cortex contributed to neonatal pain-induced hearing impairment and dendritic pruning deficiency in mice

INTRODUCTION

Procedural pain in neonates is associated with impaired neurodevelopment. Whether hearing development is impaired, however, remains unknown. This study examined potential cause-and-effect relationship between neonatal pain and subsequent hearing loss in mice.

METHODS

Male C57BL/6J mouse pups received an intra-plantar injection of complete Freund's adjuvant on postnatal day 7 or repetitive needle prick stimuli from postnatal days 0-7. Mechanical and thermal pain thresholds were tested between postnatal days 14 and 49. The auditory brainstem response test was used to determine hearing thresholds. The inner ear structures and dendritic morphology in auditory cortex were assessed using immunofluorescence and Golgi-staining. The effects of oxycodone, tropomyosin receptor kinase B agonists and antagonists were tested.

RESULTS

Neonatal pain resulted in impaired hearing in adulthood of both pain models No damage or synapse loss was found in the cochlea but increased dendritic spine density and reduced brain-derived neurotrophic factor level were found in auditory cortex in neonatal pain group. Oxycodone attenuated hearing loss and the associated changes in dendritic spine density and brain-derived neurotrophic factor changes in auditory cortex. A tropomyosin receptor kinase B agonist reversed neonatal pain-induced hearing impairment and decreased caspase 3 expression in auditory cortex. Administration of tropomyosin receptor kinase B antagonist in naïve mouse pups impaired hearing development suppressed phosphorylated-AKT, and increased caspase 3 expression.

CONCLUSION

Chronic pain during the neonatal period resulted in impaired hearing in adulthood in mice, possibly via the brain-derived neurotrophic factor signaling pathway and dendritic spine pruning deficiency in auditory cortex.

Association Between Expanded Genomic Sequencing Combined With Hearing Screening and Detection of Hearing Loss Among Newborns in a Neonatal Intensive Care Unit

IMPORTANCE

Hearing loss is a global social burden. Early identification of hearing loss missed by newborn hearing screening tests in the neonatal intensive care unit is crucial.

OBJECTIVE

To assess the association between expanded genomic sequencing combined with hearing screening and detection of hearing loss as well as improvement in the neonatal intensive care unit.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study was performed between August 8, 2016, and December 31, 2020, among 8078 newborns admitted to the neonatal intensive care unit of the Children's Hospital of Fudan University in Shanghai, China. Follow-up for hearing status was performed via telephone interviews between September 1 and November 30, 2021.

EXPOSURES

A hearing screening test and the expanded genomic sequencing targeting 2742 genes were administered to each patient. Those who failed the hearing screening test or had positive genetic findings were referred for diagnostic audiometry at a median of 3 months of age.

MAIN OUTCOMES AND MEASURES

The primary outcome was hearing loss missed by hearing screening test. Secondary outcomes were genetic findings and benefits associated with the expanded genomic sequencing for clinical management of patients in the neonatal intensive care unit.

RESULTS

Of 8078 patients (4666 boys [57.8%]; median age, 6.3 days [IQR, 3.0-12.0 days]), 52 of 240 (21.7%) received a diagnosis of hearing loss. Expanded genomic sequencing combined with hearing screening was associated with a 15.6% increase (7 of 45 patients) in cases of diagnosed hearing loss that were missed by hearing screening. Of the 52 patients with hearing loss, genetic factors were identified for 39 patients (75.0%); GJB2 and SLC26A4 were the most common genes identified. Patients with genetic findings experienced a more severe degree of hearing loss than those without genetic findings (21 profound, 4 severe, 7 moderate, and 7 mild vs 2 severe, 4 moderate, and 7 mild; P = .005), with more bilateral hearing loss (39 of 39 [100%] vs 9 of 13 [69.2%]; P = .003). Clinical management strategies were changed for patients who underwent genomic sequencing combined with hearing screening.

CONCLUSIONS AND RELEVANCE

This study suggests that expanded genomic sequencing combined with hearing screening may be effective at detecting hearing loss among patients in the neonatal intensive care unit.

Receipt and Timeliness of Newborn Hearing Screening and Diagnostic Services Among Babies Born in 2017 in 9 States

CONTEXT

By providing timely services at all steps along the continuum of the early hearing detection and intervention (EHDI) process, providers may be able to lessen potential adverse effects of late identification of hearing loss on children's language development.

OBJECTIVE

To examine the timeliness of key events in the EHDI process from birth through diagnosis of hearing loss among different populations.

DESIGN

Retrospective, cross-sectional.

SETTING

Data pooled from 9 states' EHDI information systems were used to determine the extent to which timely screening and diagnosis were achieved by 754 613 infants born in calendar year 2017. Enrollment into early intervention for children diagnosed is not examined here due to incomplete data.

PARTICIPANTS

Nine state EHDI programs were selected to participate in this study for their successful experience in using EHDI-IS to collect detailed child-level data.

MAIN OUTCOME MEASURES

Age of service, rate of service receipt.

RESULTS

Median age of newborn hearing screening was 1 day, and median age of hearing loss diagnosis was 68 days. Early completion of newborn hearing screening was associated with maternal education, maternal race/ethnicity, and admission into a neonatal intensive care unit (NICU). Receiving and completing follow-up diagnostic services were associated with maternal education, maternal race/ethnicity, age of screening, and enrollment into the Women, Infants, and Children program.

CONCLUSIONS

Timely completion of the newborn hearing screening is achieved by most of the population among the participating states. Increased efforts may be considered by state EHDI programs to provide additional follow-up and education to underrepresented racial/ethnic groups, mothers with less education, and NICU infants and their families as these groups appear to be at an increased risk for delayed diagnostic testing for hearing loss.

The Effects of Clinical Factors and Neonatal Morbidities on Hearing Screening among Neonatal Admissions

BACKGROUND

Hearing loss is an important disorder affecting newborns admitted to NICU. A national hearing screening program using otoacoustic emission testing is an essential tool to identify hearing loss early in neonates, enabling early intervention to avoid further challenges of pediatric deafness. On the other hand, a delay of the auditory pathway maturation in preterm babies compared to term newborns has already been suggested in the literature. Taking this information into account, in this paper, we aim to identify the best time to perform NICU infant hearing screening tests.

OBJECTIVES

We aim to study the clinical factors and neonatal morbidities that may affect neonatal hearing screening results using otoacoustic emission test in order to decrease the false-positive test results that increase parental anxiety and increase the need for subsequent investigations.

METHODS

This is a prospective cross-sectional study that included 204 infants who were admitted to a tertiary referral hospital NICU unit between September 2017 and May 2018. Both transients evoked otoacoustic emissions (TEOAE), and distortion product otoacoustic emission (DPOAE) screening tests were performed in order to screen hearing loss.

RESULTS

Our study included 204 infants, 52.9 % of which were males and 47.1 % females. There were correlations between both hyperbilirubinemia and ventilation ≥ 5 days and the failure rate of the first OAE test results among NICU infants where the P-values were (p=0.0133) and (p=0.0456), respectively. Moreover, 165 babies (80.9 %) passed the first OAE with a mean birth weight of 2759 gram and mean maternal age of 30.6 years, while 39 babies (19.1 %) failed the test with a mean birth weight of 2436 gram and a mean maternal age of 32 years. There was no statistically significant relation between both maternal age and birth weight with failure of the first screening test.

CONCLUSION

Our study suggests a higher failure rate of the first OAE in NICU infants who had hyperbilirubinemia or ventilation ≥ 5 days. Therefore, our recommendation is to postpone the first phase of hearing screening for those infants until the first scheduled vaccine appointment to achieve high compliance to attendance and decrease distress to the family that can be associated with false-negative results of the test.

Multiple congenital anomalies and adverse developmental outcomes are associated with neonatal intensive care admission and unilateral hearing loss

AIM

To determine congenital and developmental outcomes of children with Unilateral Hearing Loss (UHL) who were admitted to the Neonatal Intensive Care Unit (NICU).

METHOD

Retrospective, single-site study that followed 25 children with permanent congenital UHL and a NICU admission to a NICU of Nottingham University Hospital. Birth and two-year developmental follow-up data were collected. They were compared to matched control group who had a NICU admission but no hearing loss (matched on gestational age, weight and sex).

RESULTS

The median birthweights, gestational ages and number of days spent on the NICU for the UHL population were 2510 g, 36 weeks, and 12 days respectively. Most children (20/25; 80%) with UHL and a NICU admission were diagnosed with a congenital anomaly within the first two years of life. Only half (13/25) of these children were diagnosed with a congenital anomaly at discharge. Children with UHL and a NICU admission were more likely than the matched group (NICU admission only; p < .001) to have multiple congenital anomalies. We found a positive association between multiple congenital anomalies and developmental impairment for the NICU graduates with UHL (p = .019). This UHL-NICU group were also more likely than the matched NICU children to have developmental impairment (7/25 vs. 0/25; p = .01), speech and language therapy (13/25 vs. 1/25; p < .001), inner ear malformations (14/25 vs. 0/25, p < .001) or craniofacial anomalies (12/25 vs. 2/25; p = .004).

INTERPRETATION

Children with UHL and a NICU admission were at high risk of congenital anomalies and certain adverse developmental outcomes. Improved congenital anomaly screening is needed at birth for this population. Having multiple congenital anomalies suggests closer developmental monitoring is needed. This study contributes towards producing clinical screening and management guidelines to ensure consistent high-quality care for this unique population.

Retinopathy of Prematurity and Hearing Impairment in Infants Born with Very-Low-Birth-Weight: Analysis of a Korean Neonatal Network Database

Background: To investigate hearing impairment and its association with retinopathy of prematurity (ROP) among children born with very low birth weight (VLBW, birth weight < 1500 g). Methods: This prospective registry study included 7940 VLBW infants who underwent both ophthalmic (ROP) and hearing screening at the 70 participating centers of the Korean Neonatal Network. Hearing screening was performed using auditory brainstem response and/or automated otoacoustic emission testing. Hearing impairment, defined as a unilateral or bilateral hearing threshold of ≥40 dB on the auditory brainstem response threshold (ABR-T) test, was evaluated and compared between children with and without ROP at the corrected ages of 18 months and 3 years. Results: The frequency of infants who did not undergo hearing screening at near-term ages was higher in the ROP group than in the no-ROP group (18.2% vs. 12.0%, p < 0.001), and the prevalence of hearing impairment at 18 months was higher in the ROP group than in the no-ROP group (3.5% vs. 2.2%, p = 0.043). The prevalence of deafness was higher in children with ROP than those without ROP (0.4% vs. 0.1%, p = 0.049). There were significant differences in hearing impairment among the stages of ROP (p < 0.001). However, multivariate analyses and propensity score matching showed no significant association between ROP and hearing impairment at 18 months and 3 years after adjusting for prematurity-related variables (all p > 0.05). Conclusions: Among infants born with VLBW, hearing impairment was more common in those with ROP than in those without ROP at 18 months of age. However, there was no significant independent association between hearing impairment and ROP.

Permanent childhood hearing impairment in infants admitted to the neonatal intensive care unit: nested case-control study

The prevalence of permanent childhood hearing impairment (PCHI) in infants admitted to a neonatal intensive care unit (NICU) is higher than that in the general population. Our study objective was to identify risk factors associated with PCHI in infants who required admission to the NICU for more than 48 h. We performed a case-control study, including infants of all gestational ages who were admitted to NICU for more than 48 h and who underwent newborn hearing screening between 2005 and 2019. Infants admitted to NICU and diagnosed with PCHI by formal audiology were classified as "cases". The "controls" were infants who were admitted to NICU and did not have PCHI. Cases and controls (1:4) were matched based on their birth gestation, birthing place, and treating NICU. The prevalence of PCHI in infants admitted to NICU was 6.3% as compared with our general population prevalence of 0.25%. There were 77 cases and 269 controls during the study period. The median age at diagnosis of PCHI in these infants was 132 days (interquartile range 75.5-518.5). Using regression analysis, "any ventilation episodes", presence of seizures, and major congenital anomalies were significantly associated with PCHI in infants of all gestational ages. There were higher prevalence of PCHI in preterms (<32 weeks) who received furosemide and lower prevalence with antenatal use of magnesium sulphate.Conclusions: In our study, the prevalence of hearing loss was high in infants admitted to NICU. Gestation-specific risk factors identified in this case-control study would help in counselling of parents. What is Known: • In the UK, 1-2/1000 infants are born with hearing loss and infants admitted to the neonatal unit for 48 h or more have increased prevalence of hearing loss (1 in 100 live births). • Identification of risk factors in infants admitted to neonatal unit would help with risk stratification and further management. What is New: • In our study, infants admitted to the neonatal unit had higher prevalence of hearing loss (6.3 in 100 live births). • In infants across all gestational age "any ventilation episodes", presence of seizures, and severe congenital anomalies were associated with a statistically significant increase in prevalence of hearing loss. Higher prevalence of hearing loss was noted in preterm infants (<32 weeks) who received furosemide treatment and lower prevalence was noted with antenatal use of magnesium sulphate.

Association between Hyperbilirubinemia and Hearing Screen Failure in the Neonatal Intensive Care Unit in Infants Born Preterm

OBJECTIVE

To characterize the association between hyperbilirubinemia and a failed newborn hearing screen in infants born at 22-32 weeks of gestation.

STUDY DESIGN

We included infants with gestational ages of 22-32 weeks who were discharged from neonatal intensive care units in the US from 2002 to 2017 with available newborn hearing screen results obtained after 34 weeks postmenstrual age. We excluded infants with severe birth asphyxia or craniofacial abnormalities. We identified 95 672 infants from 313 neonatal intensive care units. We used multivariable logistic regression to examine the association between maximum total bilirubin at <21 days postnatal age with failed hearing screen, adjusting for important demographic and clinical risk factors.

RESULTS

The median gestational age and birth weight were 30 weeks (IQR, 28-32 weeks) and 1330 g (IQR, 1010-1630 g), respectively. The median maximum total bilirubin was 8.3 mg/dL (IQR, 6.7-10.0 mg/dL), and 5275 infants (6%) failed their newborn hearing screen. On adjusted analysis, each 1 mg/dL increase in maximum total bilirubin was associated with a small, but significant, increase in odds of a failed hearing screen (OR, 1.03; 95% CI, 1.02-1.04).

CONCLUSIONS

An increased maximum total bilirubin level was independently associated with hearing screen failure. Further prospective studies are needed to understand whether this increased risk of hearing screen failure translates to increased risk of hearing loss.