Risk indicators for congenital and delayed-onset hearing loss

A novel copy number variant in the murine Cdh23 gene gives rise to profound deafness and vestibular dysfunction

Hearing loss is the most common congenital sensory deficit worldwide and exhibits high genetic heterogeneity, making molecular diagnoses elusive for most individuals. Detecting novel mutations that contribute to hearing loss is crucial to providing accurate personalized diagnoses, tailored interventions, and improving prognosis. Copy number variants (CNVs) are structural mutations that are understudied, potential contributors to hearing loss. Here, we present the Abnormal Wobbly Gait (AWG) mouse, the first documented mutant exhibiting waltzer-like locomotor dysfunction, hyperactivity, circling behaviour, and profound deafness caused by a spontaneous CNV deletion in cadherin 23 (Cdh23). We were unable to identify the causative mutation through a conventional whole-genome sequencing (WGS) and variant detection pipeline, but instead found a linked variant in hexokinase 1 (Hk1) that was insufficient to recapitulate the AWG phenotype when introduced into C57BL/6J mice using CRISPR-Cas9. Investigating nearby deafness-associated genes revealed a pronounced downregulation of Cdh23 mRNA and a complete absence of full-length CDH23 protein, which is critical for the development and maintenance of inner ear hair cells, in whole head extracts from AWG neonates. Manual inspection of WGS read depth plots of the Cdh23 locus revealed a putative 10.4 kb genomic deletion of exons 11 and 12 that was validated by PCR and Sanger sequencing. This study underscores the imperative to refine variant detection strategies to permit identification of pathogenic CNVs easily missed by conventional variant calling to enhance diagnostic precision and ultimately improve clinical outcomes for individuals with genetically heterogenous disorders such as hearing loss.

UK and US risk factors for hearing loss in neonatal intensive care unit infants

IMPORTANCE

Early detection and intervention of hearing loss may mitigate negative effects on children's development. Children who were admitted to the neonatal intensive care unit (NICU) as babies are particularly susceptible to hearing loss and risk factors are vital for surveillance.

DESIGN, SETTING AND PARTICIPANTS

This single-centre retrospective cohort study included data from 142 inborn infants who had been admitted to the NICU in a tertiary regional referral centre. Data were recorded for 71 infants with confirmed permanent congenital hearing loss hearing loss. To determine impact of NICU admission independently of prematurity, babies were individually matched with 71 inborn infants on gestational age, birthweight, and sex.

MAIN OUTCOMES AND MEASURES

Neonatal indicators were recorded for all children with permanent congenital hearing loss. Presence of UK and US risk factors for hearing loss were collected on the neonatal population with hearing loss and for the matched controls.

RESULTS

A fifth (21%) of babies with hearing loss had one or more UK risk factors whereas most (86%) had at least one US risk factor. False positives would be evident if US factors were used whereas the matched controls had no UK risk factors. Ten babies who at birth had no UK or US risk factors did not have any significant neonatal indicators identified in their records, one was ventilated for one day and two had a genetic anomaly.

CONCLUSIONS AND RELEVANCE

Current risk factors for hearing loss we identified for follow-up in this high-risk group are highly specific for congenital hearing loss. UK risk factors were highly specific for hearing loss but not sensitive and conversely, US risk factors are sensitive but not specific so false positives would be recorded. A national study of neonatal indicators could provide the utility to test which combinations of risk factors provide high sensitivity without losing specificity.

Detecting Hearing Loss Through Targeted Surveillance: Risk Registry and Surveillance Timeframe Recommendations

PURPOSE

The purpose of this study was to inform the revision of a targeted surveillance risk registry by identifying which risk factors predict postnatally identified hearing loss (PNIHL) in children who pass newborn hearing screening and to determine whether hearing surveillance beyond the age of 1 year is warranted.

METHOD

We used retrospective analysis of the audiological outcomes of children born in the state of Queensland, Australia, between January 1, 2010, and December 31, 2019, who passed the newborn hearing screen with risk factors.

RESULTS

Approximately one third of children were lost to follow-up and could not be included in the analysis. Risk factors that predicted PNIHL in the analyzed cohort were as follows: syndromes associated with hearing loss, craniofacial anomalies, perinatal infections, and family history of permanent childhood hearing loss. Severe asphyxia did not predict PNIHL but yielded some cases of significant bilateral hearing loss. Hearing loss in children with a history of prolonged ventilation was mild and/or unilateral in nature (except in cases where the hearing loss was due to an unrelated etiology). There were no cases of PNIHL in children with hyperbilirubinemia or neonatal bacterial meningitis. For the risk factors that predicted PNIHL, nearly all hearing losses were detected by 1 year of age, except for children with family history where one quarter of hearing losses had a later onset.

CONCLUSIONS

The four risk factors recommended for efficient postnatal identification of hearing loss are as follows: syndromes associated with hearing loss, craniofacial anomalies, perinatal infection, and family history of permanent childhood hearing loss. Hearing surveillance through to 1 year old is sufficient except for children with a family history, where a second phase assessment is indicated. Alternative targeted surveillance protocols and models of care are required to minimize loss to follow-up.

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.

The prevalence and risk factors for congenital hearing loss in neonates: A birth cohort study based on CHALLENGE study

OBJECTIVES

To determine the prevalence and risk factors of congenital hearing loss (HL) in neonates based on China Longitudinal Environmental, Genetic, and Economic Cohort (CHALLENGE cohort).

METHODS

Maternal and neonatal data were collected based on the CHALLENGE cohort study from July 2018 to September 2020. Total 7287 neonates underwent the universal newborn hearing screening (UNHS). Babies who did not pass the initial screening and the rescreening were given the formal audiological diagnosis for possible HL. The data was analyzed to find out the prevalence and risk factors for congenital HL in this cohort study.

RESULTS

The prevalence of congenital HL was 3.43‰, and temporary HL was 0.07‰ (5 neonates). The statistical data showed that risk factors, including craniofacial anomalies, neonatal intensive care unit (NICU) admission, family history and advanced maternal age (AMA), could be associated with congenital HL. Additionally, exchange transfusion, assisted ventilation and NICU admission, these three factors could be associated with congenital sensorineural HL (SNHL). Risk factors including craniofacial anomalies, NICU admission, family history and AMA might be contributed to congenital conductive HL(CHL).

CONCLUSION

There were several common risk factors could be contributed to congenital HL, which were consistent with previous studies. However, some risk factors were no longer causing congenital HL due to the improvement of medical treatment and prenatal care. This study has not only helped explain the status quo of the prevalence of congenital HL in China but also laid foundation for future studies.

Prevalence and causes of paediatric hearing loss in a rural province of Zimbabwe: A cross-sectional study

BACKGROUND

Hearing loss (HL) in childhood is a significant disability with severe consequences for educational, cognitive, and social-emotional success. Nevertheless, prevalence estimates for HL in Sub-Saharan Africa (SSA) are based on scarce data. Therefore, we aimed to estimate the prevalence of HL in a sample of primary school children from a rural province of Zimbabwe.

METHODS

A cross-sectional study was performed on primary school children aged 4-13 years from a rural Zimbabwean province. In the quietest room available, participants underwent audiometry, video otoscopy, and tympanometry. Hearing loss was defined as a pure-tone average > 25 dB. Risk factors of hearing loss were evaluated via a questionnaire. Furthermore, to enable comparison with similar studies, HL prevalence was calculated according to two other commonly used definitions.

RESULTS

A total of 451 pupils were included, of which 10.6% (95% CI 7.8-13.5) met the study criteria for HL. Conductive HL (95.1%) was nineteen times more prevalent than sensorineural HL (4.9%). Otitis media was the underlying cause in 40% of all cases of HL. The prevalence of clinically significant HL varied depending on the definition applied, i.e., 0.4% (95% CI -0.2-1.0) in the worst World Health Organisation category as opposed to 4.2% (95% CI 2.4-4.1) in the worst American Speech-Hearing Association category.

CONCLUSIONS

Hearing loss was common in this sample of primary school children from a rural province in Zimbabwe.

Detecting Hearing Loss in Infants With a Syndrome or Craniofacial Abnormalities Following the Newborn Hearing Screen

Purpose The current Joint Committee on Infant Hearing guidelines recommend that infants with syndromes or craniofacial abnormalities (CFAs) who pass the universal newborn hearing screening (UNHS) undergo audiological assessment by 9 months of age. However, emerging research suggests that children with these risk factors are at increased risk of early hearing loss despite passing UNHS. To establish whether earlier diagnostic audiological assessment is warranted for all infants with a syndrome or CFA, regardless of screening outcome, this study compared audiological outcomes of those who passed UNHS and those who referred. Method A retrospective analysis was performed on infants with a syndrome or CFA born between July 1, 2012, and June 30, 2017 who participated in Queensland, Australia's state-wide UNHS program. Results Permanent childhood hearing loss (PCHL) yield was higher among infants who referred on newborn hearing screening (51.20%) than in those who passed. Nonetheless, 27.47% of infants who passed were subsequently diagnosed with hearing loss (4.45% PCHL, 23.02% transient conductive), but PCHL was generally milder in this cohort. After microtia/atresia, the most common PCHL etiologies were Trisomy 21, other syndromes, and cleft palate. Of the other syndromes, Pierre Robin sequence featured prominently among infants who passed the hearing screen and were subsequently diagnosed with PCHL, whereas there was a broader mix of other syndromes that caused PCHL in infants who referred on screening. Conclusion Children identified with a syndrome or CFA benefit from early diagnostic audiological assessment, regardless of their newborn hearing screening outcome.

Assessment of Hearing Screening Combined With Limited and Expanded Genetic Screening for Newborns in Nantong, China

IMPORTANCE

Early identification and intervention for newborns with hearing loss (HL) may lead to improved physiological and social-emotional outcomes. The current newborn hearing screening is generally beneficial but improvements can be made.

OBJECTIVE

To assess feasibility and evaluate utility of a modified genetic and hearing screening program for newborn infants.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study used a 4-stage genetic and hearing screening program at 6 local hospitals in Nantong city, China. Participants were newborn infants born between January 2016 and June 2020 from the Han population. Statistical analysis was performed from April 1 to May 1, 2021.

EXPOSURES

Limited genetic screening for 15 variants in 4 common HL-associated genes and newborn hearing screening (NHS) were offered concurrently to all newborns. Hearing rescreening and/or diagnostic tests were provided for infants with evidence of HL on NHS or genetic variants on screening. Expanded genetic tests for a broader range of genes were targeted to infants with HL with negative results of limited genetic tests.

MAIN OUTCOMES AND MEASURES

The detection capability for infants with hearing impairment who passed conventional hearing screening, as well as infants with normal hearing at risk of late-onset HL due to genetic susceptibility.

RESULTS

Among a total of 35 930 infants, 32 512 infants completed the follow-up and were included for analysis. Among the infants included in the analysis, all were from the Han population in China and 52.3% (16 988) were male. The modified genetic and hearing screening program revealed 142 cases of HL and 1299 cases of genetic variation. The limited genetic screening helped identify 31 infants who passed newborn hearing screening, reducing time for diagnosis and intervention; 425 infants with normal hearing with pathogenic SLC26A4 variation and 92 infants with MT-RNR1 variation were at risk for enlarged vestibular aqueduct and aminoglycoside-induced ototoxicity respectively, indicating early aversive or preventive management.

CONCLUSIONS AND RELEVANCE

This study found that performing modified genetic and hearing screening in newborns was feasible and provides evidence that the program could identify additional subgroups of infants who need early intervention. These findings suggest an advantage for universal adoption of such a practice.

Neonatal and maternal risk factors for hearing loss in children based on population-based data of Korea

OBJECTIVES

We identified the neonatal and maternal risk factors for hearing loss (HL) in children using National Health Insurance Service data of Korea.

METHODS

We retrospectively analyzed data from the National Health Insurance Service. Infants born from 2007 to 2013 were tracked to 2015. Those diagnosed with hearing disabilities or who underwent cochlear implant surgery were included in the hearing disability group. We compared the incidence of any diagnosed disability other than a hearing disability; any maternal disability at delivery; maternal age at delivery; prenatal and neonatal Toxoplasma, syphilis, rubella, cytomegalovirus, and herpes simplex infections; craniofacial anomaly; low birth weight, hyperbilirubinemia, and bacterial meningitis; neonatal intensive care unit (NICU) admission for > 5 days; exchange transfusion; and ototoxic drug use (aminoglycosides or loop diuretics), between the hearing disability and control groups.

RESULTS

The total number of newborns came to 3,164,825. Risk factors were sought in a hearing disability group (n = 847) compared to a control group (n = 2508). A diagnosed disability other than a hearing disability, which was commonly a brain lesion, the use of ototoxic drugs, NICU admission for >5 days, and a maternal disability at delivery, which was commonly a hearing disability, were significant neonatal and maternal risk factors for HL in children.

CONCLUSIONS

Accompanying brain lesions, maternal hearing disabilities at delivery, use of ototoxic drugs during the neonatal period, and hospitalization in NICU for >5 days were significant risk factors for HL in children, as revealed by analysis of population-based data.

Analysis of the Risk Factors Associated with Hearing Loss of Infants Admitted to a Neonatal Intensive Care Unit: A 13-Year Experience in a University Hospital in Korea

Early detection of hearing loss in neonates is important for normal language development, especially for infants admitted to the neonatal intensive care unit (NICU) because the infants in NICU have a higher incidence of hearing loss than healthy infants. However, the risk factors of hearing loss in infants admitted to the NICU have not been fully acknowledged, especially in Korea, although they may vary according to the circumstances of each country and hospital. In this study, the risk factors of hearing loss in NICU infants were analyzed by using the newborn hearing screening (NHS) and the diagnostic auditory brainstem response (ABR) test results from a 13-year period. A retrospective chart review was performed using a list of NICU infants who had performed NHS from 2004 to 2017 (n = 2404) in a university hospital in Korea. For the hearing loss group, the hearing threshold was defined as 35 dB nHL or more in the ABR test performed in infants with a 'refer' result in the NHS. A four multiple number of infants who had passed the NHS test and matched the age and gender of the hearing loss group were taken as the control group. Various patient factors and treatment factors were taken as hearing loss related variables and were analyzed and compared. From the 2404 infants involved, the prevalence of hearing loss was 1.8% (n = 43). A comparison between the hearing loss group (n = 43) and the control group (n = 172) revealed that history of sepsis, peak total bilirubin, duration of vancomycin use, days of phototherapy, and exposure to loop-inhibiting diuretics were significantly different, and can be verified as significant risk factors for hearing loss in NICU infants.

Prevalence and risk factors for delayed-onset hearing loss in early childhood: A population-based observational study in Okayama Prefecture, Japan

OBJECTIVES

The aim of this study was to retrospectively document prevalence rates of delayed-onset hearing loss (DOHL) under 7 years old after passing the newborn hearing screening (NHS) program using its database in Okayama Prefecture, as well as records from Okayama Kanariya Gakuen (OKG, Auditory Center for Hearing Impaired Children, Okayama Prefecture, Japan). We explored the percentage of children with DOHL among all children who underwent the NHS and surveyed risk factors abstracted from their clinical records.

METHODS

We collected data of 1171 children, who first visited OKG from April 2006 to March 2018. DOHL children were defined as bilaterally hearing-impaired children who were diagnosed under 7 years old after passing the NHS at birth. Based on the medical records, we investigated age at diagnosis, hearing levels, and risk factors. As population-based data of 168,104 children, the percentage of DOHL subjects was retrospectively calculated among the total number of children who underwent the NHS in Okayama Prefecture from April 2005 to March 2017.

RESULTS

During the period, we identified 96 children with bilateral DOHL, of which 34 children had failed the NHS unilaterally and 62 had passed the NHS bilaterally. Among all children who underwent the NHS in Okayama Prefecture, the prevalence rate of DOHL in unilaterally referred infants was 5.2%, and 0.037% in bilaterally passed children. The prevalence of bilateral DOHL was 0.057% overall. Unilaterally referred children with DOHL were diagnosed at an average of 13.9 months, while bilaterally passed children with DOHL were diagnosed at an average of 42.3 months. Approximately 59.4% of children with DOHL had risk factors, among which family history of hearing loss was the most frequent.

CONCLUSION

We propose the first English report of DOHL prevalence in the prefecture population in Japann, which is among the largest community-based population ever reported. The NHS is not a perfect strategy to detect all early-childhood hearing loss; therefore, careful assessment of hearing throughout childhood is recommended, especially in children with risk factors of hearing loss. Further interventional strategies must be established, such as regular hearing screening in high-risk children and assessments of hearing and speech/language development in public communities and nursery schools.

Adherence to follow-up recommendations for babies at risk for pediatric hearing loss

OBJECTIVE

The purpose of this retrospective study was to evaluate the families' compliance with recommendations for continued monitoring of babies with high-risk factors for hearing loss.

METHODS

Hearing screening and follow-up results from 604 babies were tracked across a five-year period. Bivariate analysis, including chi-square analysis, t-tests, and one-way analyses of variance were conducted to test whether various factors predicted likelihood of follow up.

RESULTS

Although 86% of the babies returned for the initial follow-up appointment, few completed the protocol or were diagnosed with hearing loss (10.3%). Excluding the babies who never returned, the average age for initial assessment was near the recommended 3-month target (3.5 months). However, babies were last seen at 9.4 months on average, which is earlier than recommended. Some factors positively predicted follow-up: receipt of ototoxic medication, hyperbilirubinemia requiring transfusion, ECMO, syndromes associated with hearing loss, craniofacial anomalies, and passing the newborn hearing screening. Others were negatively predictive: NICU stay >5 days, younger maternal age, and failing the newborn screening. There was no relationship between the results of the last test and whether the families continued with monitoring. Babies with risks categorized as more likely to be associated with delayed onset hearing loss were more often late to the initial follow up, but also followed up for a longer period of time.

CONCLUSIONS

These results demonstrate the need to focus on the barriers unique to babies with risk factors for late onset/progressive hearing loss in addition to those barriers that generally affect loss to follow up. Tools for parental engagement are recommended.

Treatment for hypotension in the first 24 postnatal hours and the risk of hearing loss among extremely low birth weight infants

OBJECTIVE

To evaluate whether treated hypotension in the first 24 postnatal hours is associated with hearing loss in extremely low birth weight (ELBW) infants.

STUDY DESIGN

In a cohort of 735 ELBW infants, we identified 25 with sensorineural hearing loss (SNHL) at 12-24 months adjusted age. For each case, we selected three controls with normal hearing. Logistic regression models were used to adjust for confounding variables.

RESULTS

Sixty percent of cases and 25% of controls were treated for hypotension. After adjusting for confounding variables (gestational age, antenatal glucocorticoids, 5 min Apgar < 6, insertion of an umbilical catheter, treatment with high frequency ventilation, and major cranial ultrasound abnormality), treated hypotension was associated with an increased risk of SNHL (adjusted odds ratio: 3.6; 95% confidence interval: 1.3-9.7).

CONCLUSIONS

Treated hypotension in ELBW infants in the first 24 h of life is associated with an increased risk of SNHL.

Medical Referral Patterns and Etiologies for Children With Mild-to-Severe Hearing Loss

OBJECTIVES

To (1) identify the etiologies and risk factors of the patient cohort and determine the degree to which they reflected the incidence for children with hearing loss and (2) quantify practice management patterns in three catchment areas of the United States with available centers of excellence in pediatric hearing loss.

DESIGN

Medical information for 307 children with bilateral, mild-to-severe hearing loss was examined retrospectively. Children were participants in the Outcomes of Children with Hearing Loss (OCHL) study, a 5-year longitudinal study that recruited subjects at three different sites. Children aged 6 months to 7 years at time of OCHL enrollment were participants in this study. Children with cochlear implants, children with severe or profound hearing loss, and children with significant cognitive or motor delays were excluded from the OCHL study and, by extension, from this analysis. Medical information was gathered using medical records and participant intake forms, the latter reflecting a caregiver's report. A comparison group included 134 children with normal hearing. A Chi-square test on two-way tables was used to assess for differences in referral patterns by site for the children who are hard of hearing (CHH). Linear regression was performed on gestational age and birth weight as continuous variables. Risk factors were assessed using t tests. The alpha value was set at p < 0.05.

RESULTS

Neonatal intensive care unit stay, mechanical ventilation, oxygen requirement, aminoglycoside exposure, and family history were correlated with hearing loss. For this study cohort, congenital cytomegalovirus, strep positivity, bacterial meningitis, extracorporeal membrane oxygenation, and loop diuretic exposure were not associated with hearing loss. Less than 50% of children underwent imaging, although 34.2% of those scanned had abnormalities identified. No single imaging modality was preferred. Differences in referral rates were apparent for neurology, radiology, genetics, and ophthalmology.

CONCLUSIONS

The OCHL cohort reflects known etiologies of CHH. Despite available guidelines, centers of excellence, and high-yield rates for imaging, the medical workup for children with hearing loss remains inconsistently implemented and widely variable. There remains limited awareness as to what constitutes appropriate medical assessment for CHH.

Predicting hearing loss in children according to the referrer and referral cause

BACKGROUND

Hearing assessment in children is considered necessary in all cases involving a doubt regarding hearing acuity. Due to the fact that the number of referrals may be much greater than the actual capacity of a hearing institute, it would be desirable to have a filtering tool in order to detect the cases with higher suspicion of hearing loss.

OBJECTIVE

To evaluate whether anamnesis details can be used as a sorting tool for detection of highly suspicious cases of hearing loss in preschool children. The anamnesis details may be one or more of the following: the reason for performing hearing test, which caregiver indicated the need for hearing evaluation, the parent's comprehension of their child hearing, and the medical history.

METHODS

the parents of preschool children, who were referred to the hearing institute at Soroka university medical center, were asked to fill a questionnaire containing 18 questions. The questions referred to details such as: the reason for performing the hearing test; who suggested the existence of hearing impairment; medical history issues and questions regarding details that may indicate a risk of hearing loss. Details such as Otoscopy results were taken from the medical record of the patient.

RESULTS

317 preschool and school patients were recruited to the study. Hearing loss was found in 42% of the cases. The most common reason for performing the hearing test was speech disturbance (33%). In cases which the parents were those who raised the suspicion of hearing loss - hearing impairment was found in 61% of the cases, compared to 36% when the speech therapist was the one raising the doubts and to only 18% when the kindergarten teacher was the one raising the doubt. The positive predictive value of patient that their parents suspected the hearing loss combined with pathologic otoscopy result was 82.6% when the reason for the test was hearing impairment suspicion, and 91.3% when the reason for the hearing test was speech disturbance.

CONCLUSIONS

Parents are the best in assessing their child's hearing followed by the speech therapist and the least sensitive is the school teacher.

Impact of Diuretic Therapy in the Treatment of Bronchopulmonary Dysplasia and Acute Kidney Injury in the Neonatal Population

BACKGROUND

Diuretics are among the most frequently prescribed medications in the neonatal intensive care unit (NICU), despite minimal data regarding the safety and efficacy of their use in the neonatal population. Off-label diuretic therapy is used in preterm and full-term infants to both optimize kidney function and improve respiratory status.

PURPOSE

This article examines the literature specific to the impact of diuretic therapy in the NICU and compares the benefits versus risks of utilization as they pertain to the prevention and treatment of renal and pulmonary dysfunction in this population.

METHODS/SEARCH STRATEGY

A comprehensive literature search of online databases was performed, utilizing: CINAHL via EBSCO, PubMed, and ProQuest. Full-text, peer-reviewed, clinical trials, and review articles published in the English language between 2005 and 2015 were searched.

FINDINGS/RESULTS

Diuretics rank as the seventh most frequently prescribed medication in the NICU. More than 8% of all NICU patients and 37% of infants born at less than 32 gestational weeks and weighing less than 1500 g are exposed to diuretics. Benefits include lung fluid resorption acceleration, improved urine output, fluid retention counteraction, and augmentation of physiologic weight loss.

IMPLICATIONS FOR PRACTICE

Diuretics are currently utilized in the NICU at an alarming rate, without adequate clinical trials regarding their safety and efficacy of use.

IMPLICATIONS FOR RESEARCH

Updated studies are needed regarding short- and long-term outcomes of diuretic use, as well as overall general outcome data regarding the impact and evaluation of diuretic usage in the NICU population.

High Risk Factors Associated With Early Childhood Hearing Loss: A 3-Year Review

PURPOSE

In this study, we examined the association between risk factors for hearing loss and early childhood hearing status (normal hearing, congenital hearing loss, or delayed-onset hearing loss). Follow-up rates of audiologic care following passed or referred birth screens for children with risk factors were also examined.

METHOD

A retrospective data review was completed on 115,039 children born from 2010 to 2012. Data analyses included prevalence rates, odds ratios, and Fisher exact tests of statistical significance.

RESULTS

Ninety percent of children were born with no risk factors for hearing loss; of those, 99.9% demonstrated normal hearing by 3 years of age. Of the 10% of children born with risk factors, 96.3% demonstrated normal hearing by age 3, 1.4% presented with congenital hearing loss, and 2.3% demonstrated permanent hearing loss by age 3. Factors that placed children at the highest risk of congenital hearing impairment were neurodegenerative disorders, syndromes, and congenital infections. Factors that placed children at the highest risk of developing permanent postnatal hearing loss were congenital cytomegalovirus, syndromes, and craniofacial anomalies.

CONCLUSIONS

Certain risk factors place a child at significantly greater risk of congenital hearing impairment or developing permanent hearing loss by age 3. Follow-up diagnostic testing should remain a priority for children with certain risk factors for hearing loss.

Risk Factors for Congenital Hearing Loss: Which Are the Most Relevant?

Introduction:Congenital hearing loss is a multifactorial disease that affects mostly premature newborns exposed to certain risk factors. The recent widespread introduction of newborn hearing screening in Tîrgu Mureş, Romania prompted the need for a multidisciplinary centralized study on the subject.

Case series presentation:We collected data from 340 neonates born in 2014 who had undergone neonatal hearing screening with otoacoustic emissions. Our focus group consisted of 137 neonates with a gestational age of less than 37 weeks. We collected data on the pregnancy, birth, and perinatal period, and then analyzed the impact of infections, treatments — with or without ototoxic potential, hypoxia, mechanical ventilation, intrauterine malnutrition, and the presence of malformations. Premature neonates showed a significantly higher number of REFER results than those with a normal gestational age. The rates of low birthweight, head circumference, and infant length; low Apgar scores; hypoxia in the perinatal period; the presence of placental pathology, mechanical ventilation, and perinatal infections; and the concomitant potentially ototoxic treatment were significantly higher in the REFER group. The age of the mother, bilirubin levels, and oxytocin use during birth did not prove to be relevant.

Conclusions:Known risk factors can cause hearing loss in a considerable number of newborns and mandate a multidisciplinary approach to the problem at hand. The referral of these patients to an ENT specialist and their correct management according to an individualized hearing recovery plan is crucial

Newborn hearing screening programme in Belgium: a consensus recommendation on risk factors

Background

Understanding the risk factors for hearing loss is essential for designing the Belgian newborn hearing screening programme. Accordingly, they needed to be updated in accordance with current scientific knowledge. This study aimed to update the recommendations for the clinical management and follow-up of newborns with neonatal risk factors of hearing loss for the newborn screening programme in Belgium.

Methods

A literature review was performed, and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system assessment method was used to determine the level of evidence quality and strength of the recommendation for each risk factor. The state of scientific knowledge, levels of evidence quality, and graded recommendations were subsequently assessed using a three-round Delphi consensus process (two online questionnaires and one face-to-face meeting).

Results

Congenital infections (i.e., cytomegalovirus, toxoplasmosis, and syphilis), a family history of hearing loss, consanguinity in (grand)parents, malformation syndromes, and foetal alcohol syndrome presented a ‘high’ level of evidence quality as neonatal risk factors for hearing loss. Because of the sensitivity of auditory function to bilirubin toxicity, hyperbilirubinaemia was assessed at a ‘moderate’ level of evidence quality. In contrast, a very low birth weight, low Apgar score, and hospitalisation in the neonatal intensive care unit ranged from ‘very low’ to ‘low’ levels, and ototoxic drugs were evidenced as ‘very low’. Possible explanations for these ‘very low’ and ‘low’ levels include the improved management of these health conditions or treatments, and methodological weaknesses such as confounding effects, which make it difficult to conclude on individual risk factors. In the recommendation statements, the experts emphasised avoiding unidentified neonatal hearing loss and opted to include risk factors for hearing loss even in cases with weak evidence. The panel also highlighted the cumulative effect of risk factors for hearing loss.

Conclusions

We revised the recommendations for the clinical management and follow-up of newborns exhibiting neonatal risk factors for hearing loss on the basis of the aforementioned evidence-based approach and clinical experience from experts. The next step is the implementation of these findings in the Belgian screening programme.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-015-0479-4) contains supplementary material, which is available to authorized users.