Audiologic profile of infants at risk: experience of a Western Sicily tertiary care centre

The Hearing Status of Preterm Infant’s ≤ 34 Weeks as Revealed by Otoacoustic Emissions (OAE) Screening and Diagnostic Brainstem Evoked Response Audiometry (BERA): A Tertiary Center Experience

To know the prevalence of hearing loss in preterm infants & to evaluate the sensitivity & specificity of otoacoustic emission (OAE) in detecting hearing loss in preterm infants ≤ 34 weeks. A total of 70 preterm babies from 28 to 34 weeks of gestational age were enrolled in the study. Detailed prenatal, perinatal, postnatal & family history and physical examination of the babies were carried out. First OAE was done at discharge or two weeks after birth, whichever was earlier and the second OAE assessment was done at 36-40 weeks of corrected age. Diagnostic brainstem evoked response audiometry (BERA) was done in all infants at 36-40 weeks of corrected age, at the time of second OAE. Neonates with hearing impairment were advised for early hearing aid amplification and were referred to the rehabilitation center for further management. The sensorineural hearing loss (SNHL) in either one of the ears was identified in 13 (18.57%) preterm babies. Bilateral profound SNHL was found in 5 (7.14%) babies. Auditory neuropathy profile was found in 7 (53.8%) out of 13 babies who had hearing loss. The sensitivity, specificity, positive and negative predictive values of second TEOAE compared with diagnostic BERA was 46.15%, 85.96%, 42.85%, and 87.5% respectively. Neonatal jaundice (p = 0.009) and history of exchange transfusion (p = 0.019) were found to be significant risk factors of hearing loss in our study. Other risk factors like mode of delivery, birth asphyxia, low APGAR score, meningitis, ototoxic drugs, and seizures were not associated with hearing loss. The prevalence of hearing loss in preterm infants < 34 weeks is very high. OAE alone is not an ideal screening test for high-risk neonates ≤ 34 weeks because of its low sensitivity. OAE combined with diagnostic BERA should be done in all high-risk infants preterm neonates ≤ 34 weeks to identify cases of auditory neuropathy spectrum disorders.

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.

Predicting hearing loss from 10 years of universal newborn hearing screening results and risk factors

OBJECTIVE

This study investigated whether demographic variables, risk factor presence or absence and universal newborn hearing screening (UNHS) results can be used to predict permanent childhood hearing loss (PCHL) in infants referred from screening.

DESIGN

Retrospective analysis of a UNHS database.

STUDY SAMPLE

Data were extracted from the state-wide UNHS database storing details of the 613,027 infants who were born in Queensland, Australia between 1 January 2007 and 31 December 2016 and participated in UNHS. This study included the 6735 children who were referred from the UNHS program for diagnostic audiology due to failing the screen in one or both ears or bypassing screening.

RESULTS

Factors with a significant positive association with PCHL that were incorporated into a logistic regression model were: female gender, non-indigenous status, family history of PCHL, craniofacial anomalies and syndromes associated with PCHL, and a bilateral refer result on screening.

CONCLUSIONS

Odds of PCHL vary among infants referred for diagnostic assessment from UNHS programs. When an infant refers on the newborn hearing screen, information about their gender, indigenous status, identified risk factors and specific screening outcome can be used to predict the likelihood of a congenital PCHL diagnosis.

Changes in auditory function in premature children: A prospective cohort study

OBJECTIVES

To analyze the age-specific pattern of auditory function in preterm children as a function of their gestational age at birth.

STUDY DESIGN

longitudinal cohort study.

METHODS

a prospective cohort study involved 271 preterm children aged from 6 months to 15 years old. Children were divided into two groups: 70 children with a gestational age at birth of 32-36 weeks (Group 1) and 201 children with a gestational age of 22-31 weeks (Group 2). Hearing was assessed by ABR, ASSR, OAE, behavioral audiometry, and pure tone audiometry. Additionally, for some children, CT, MRI, and GBJ2 evaluations were performed. Assessments of hearing impaired children were performed 3-4 times a year for children under 2 years of age; 2-3 times a year for children from 2 to 5 years of age; and 1-2 times a year for children over 5 years of age. Infants without any hearing problems were examined 2-3 times during their first year of life, followed by annual examinations as they aged.

RESULTS

The initial hearing examination identified SNHL and ANSD in 18 children (25.7%) and 64 children (31.8%) in Group 1 and Group 2, respectively. No significant difference in the occurrence of auditory impairment in the two groups was found at the initial assessment (p > 0.05). Further long-term follow-up revealed changes in hearing in 16 children: 15 from Group 2 and only one child from Group 1. Four different kinds of hearing changes were noted: hearing recovery to normal levels in children with ANSD; late onset hearing loss; the transformation of ANSD to SNHL, and vice versa. The age, factors, and possible mechanisms of such changes are discussed in the article.

CONCLUSION

The auditory function in prematurely born children tends to be unstable, especially at a very early age. In very preterm infants, it may either deteriorate or improve. Infants born before 31 weeks' gestation require long-term follow-up at least until they are 3-4 years of age. Caution is advised regarding very early cochlear implantation for children born before 32 weeks of gestation age.

[Psychoacoustic methods in diagnosis of central auditory processing disorders in prematurely born children]

INTRODUCTION

The presence of numerous perinatal risk factors and comorbid pathology in prematurely born children, even in the absence of peripheral auditory deficit, can lead to disruptions in the processes of higher nervous sound information processing with the formation of central auditory disorders.

OBJECTIVE

Audiological assessment of the functional state of auditory system central parts in prematurely born children.

MATERIAL AND METHODS

The study involved 54 deeply premature born infants, which were divided into 3 groups depending on age (6-7, 8-9, and 10-11 years), 18 subjects in each group, and 70 healthy, term-born children of the corresponding age. In addition to the traditional audiological examination, all children underwent an assessment of functional state of the central parts of auditory system through a pause detection test (Random Gap Detection Test, RGDT); the perception of fast rhythmic sequences of stimuli, monaural low excess speech testing, binaural interaction test in alternating binaural speech format (ABS ), dichotic presentation of pairs of single digits, single digits and monosyllables, two-digit numerals, Russian matrix phrasal test in noise (RUMatrix) were studied.

RESULTS

Prematurely born infants of all age groups were significantly worse compared to control group (p<0.01) while having RGDT, a test for assessing the perception of fast rhythmic sequences of stimuli and dichotic binaural integration tests. Monaural intelligibility of monosyllabic words in silence in children of all three groups did not differ from normal values, but it suffered from contralateral use of noise interference in children aged 6-7. According to the RUMatrix test, legibility of phrases in noise was impaired in 65% of subjects. Test results in the ABS format revealed a significant violation of speech intelligibility (p<0.01) only in children of the younger age group.

CONCLUSION

In prematurely born children, there is a dysfunction of the central parts of the auditory system, which is multilevel in nature, partially leveling as children grow older. Moreover, the processes of temporary processing of acoustic information suffer to the greatest extent, not being compensated up to adolescence.

Newborn hearing screening protocols and their outcomes: A systematic review

OBJECTIVE

To conduct a review of the most current research in objective measures used within newborn hearing screening protocols with the aim of exploring the actual protocols in terms of the types of measures used and their frequency of use within a protocol, as well as their outcomes in terms of sensitivity, specificity, false positives, and false negatives in different countries worldwide.

METHODS

A systematic literature review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. Electronic databases such as PubMed, Google Scholar and Science Direct were used for the literature search. A total of 422 articles were identified, of which only 15 formed part of the current study. The 15 articles that met the study's criteria were reviewed. Pertinent data and findings from the review were tabulated and qualitatively analysed under the following headings: country; objective screening and/or diagnostic measures; details of screening protocol; results (including false positive and negative findings, sensitivity and/or specificity), conclusion and/or recommendations. These tabulated findings were then discussed with conclusions and recommendations offered.

RESULTS

Findings reported in this paper are based on a qualitative rather than a quantitative analysis of the reviewed data. Generally, findings in this review revealed firstly, that there is a lack of uniformity in protocols adopted within newborn hearing screening. Secondly, many of the screening protocols reviewed consist of two or more tiers or stages, with transient evoked otoacoustic emissions (TEOAEs) and automated auditory brainstem response (AABR) being most commonly used. Thirdly, DPOAEs appear to be less commonly used when compared to TEOAEs. Lastly, a question around routine inclusion of AABR as part of the NHS protocol remains inconclusively answered.

CONCLUSIONS

There is sufficient evidence to suggest that the inclusion of AABR within a NHS programme is effective in achieving better hearing screening outcomes. The use of AABR in combination with OAEs within a test-battery approach or cross-check principle to screening is appropriate, but the inclusion of AABR to facilitate appropriate referral for diagnostic assessment needs to be systematically studied.

[Age-specific dynamics of the auditory function in the extremely premature babies]

Extremely early premature babies (i.e. those born before the 32^nd week of pregnancy) constitute a group at high risk of development of the perceptive forms of hearing impairment represented mostly by chronic sensorineural hearing loss (CSNHL) and hearing neuropathy (HN). The timely diagnostics of these hearing disorders in premature children and, accordingly, their early and adequate rehabilitation provide a basis for the prevention of hearing and speech problems. At the same time, the hearing function in prematurely born babies is known to be highly unstable and can undergo substantial changes with age; these changes are most frequently observed during the early childhood. This paper was designed to report the results of observations of the hearing function dynamics in a cohort of the extremely early premature children. A total of 186 babies were available for the examination. It was shown that 14 (7.5%) of them had hearing problems. They disappeared by the 12^th and 24^th months of life in 3 children. Three other babies experienced transformation of NH into CSNHL at the age of 12, 14, and 18 months. NH transformed into CSNHL in three children by the age of 12, 24, and 48 months. Five children developed delayed CSNHL by the 10^th, 15^th, 24^th, 28^th, and 36^th months of the actual life. These findings give evidence that the extremely premature children may experience both the improvement of the hearing function due largely to the processes of maturation in the auditory system and its deterioration or delayed formation of hearing impairment. It is concluded that the extremely early premature children born before the 32^nd week of pregnancy should remain under the dynamic audiological observation at least as long as the third or fourth years of life.

Study of brainstem auditory evoked potentials in early diagnosis of congenital toxoplasmosis

INTRODUCTION

Congenital toxoplasmosis is an infectious disease with high prevalence in tropical countries. It is characterized by neurological, ophthalmological and auditory sequelae.

OBJECTIVE

The aim of this study was to evaluate and describe the brainstem auditory evoked potential in infants aged 1-3 months diagnosed with congenital toxoplasmosis and to compare them with infants of the same age group without the infection.

METHODS

This is an observational, analytical and cross-sectional study in which brainstem auditory evoked potential was investigated in infants with congenital toxoplasmosis. The following audiological exams were performed: transient-evoked otoacoustic emissions, clinical and automatic brainstem auditory evoked potential.

RESULTS

100 children participated in the study, but the final sample consisted of 76 children. Of the 37 children with toxoplasmosis included in the study, 28 completed the neurological imaging evaluation, and of these, 3 (10.7%) showed an altered neurological examination. At the brainstem auditory evoked potential assessment, two children without toxoplasmosis and 10 children with congenital toxoplasmosis had results suggestive of alterations in the brainstem auditory pathway maturation.

CONCLUSION

10 (27%) children were identified with a possible unilateral alteration in the electrophysiological assessment. There was a 5-fold higher risk for a child between 1 and 3 months of age with toxoplasmosis to have an altered brainstem auditory evoked potential compared to a child of the same age range without the infection.

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.

Delayed-onset hearing loss in pediatric candidates for cochlear implantation

The objective of this study was to evaluate the clinical significance of delayed-onset hearing loss in children. Seventy-three children who underwent cochlear implantation (CI) were included. They were divided into a congenital hearing loss group (n = 50) and a delayed-onset hearing loss group (n = 23). The age at diagnosis of hearing loss, age at the beginning of auditory habilitation, the age at CI, and the postimplant speech perception abilities were compared between the two groups. Children in the congenital hearing loss group were confirmed to have hearing loss at a mean age of 0.3 years, and those in the delayed-onset hearing loss group were diagnosed with hearing loss at a mean age of 2.0 years. Auditory habilitation began at a mean age of 0.4 and 2.0 years, and CI was performed at a mean age of 1.4 and 2.6 years, respectively. Children in the congenital hearing loss group had better scores on speech perception tests than those in the delayed-onset hearing loss group, but the differences were not significant. About half of the children with delayed-onset hearing loss (57 %) had risk factors associated with delayed-onset hearing loss. A high prevalence of delayed-onset hearing loss was noted in the group of children who underwent CI. Risk factors for hearing loss were not found in 43 % of children with delayed-onset hearing loss. Universal screening for delayed-onset hearing loss needs to be performed during early childhood.

Neonatal hearing screening: what we have achieved and what needs to be improved

OBJECTIVE

To review the literature on neonatal hearing screening and its weaknesses with regard to missed follow-ups and delayed diagnosis and management.

RESULTS

The implementation of newborn hearing screening programs has indeed lowered the mean age of hearing loss identification and many deaf children are now diagnosed at an early age of some months. However, the present collection of 32 studies published in the International Journal of Pediatric Otorhinolaryngology revealed that late-onset deafness, auditory neuropathy, and the alarming percentage of newborns who fail the initial testing and then are lost to follow-up are major weaknesses of neonatal hearing screening programs. It seems that parents may be satisfied of hearing screening but in a significant percentage of them do not bring their children for follow-up or further testing due to phycho-social or other reasons. In addition, the same collection revealed that socioeconomic factors may have a significant influence on the effectiveness of hearing screening programs in the developed and developing countries, where improvements in health care politics, tracking system and public awareness is crucial for successful program implementation.

CONCLUSIONS

Neonatal hearing screening programs have changed the whole picture of congenital deafness as age identification has significantly fallen with a very positive effect on timely management. However, the selected and proposed 32 related articles published in the International Journal of Pediatric Otorhinolaryngology show that there are still serious weakness in the neonatal hearing screening that need improvements in order to achieve an efficient and cost-effective system of deafness identification.

A genotype-phenotype correlation in Sicilian patients with GJB2 biallelic mutations

The aim of this work was to study the genotype distribution of Sicilian patients with biallelic GJB2 mutations; to correlate genotype classes and/or specific mutations of GJB2 gene (35delG-non-35delG) with audiologic profiles. A total of 10 different mutations and 11 different genotypes were evidenced in 73 SNHL subjects; 35delG (90.36 % of cases) and IVS1+1 (13.69 %) were the most common mutations found in the cohort with a significant difference in the distribution between North and South Sicily. Audiological evaluation revealed a severe (16/73) to profound (47/73) hearing loss (HL) in 86.13 % of cases without significant difference between the degree of HL and the province of origin of the subjects (P = 0.727). The homozygous truncating (T/T) genotype was the most widespread (89.04 % of cases), with a severe-to-profound hearing impairment in 90.36 % of T/T class with respect to truncating/non-truncating (T/NT) and non-truncating/non-truncating (NT/NT) genotypes (P = 0.012). From the comparison of homozygous 35delG and 35delG/non-35delG genotypes, a more profound HL in the homozygous 35delG than in compound heterozygous 35delG/non-35delG (p < 0.0001) resulted. This study confirms that 35delG is the most common mutation in the Mediterranean area with a heterogeneous distribution of the genotypes between North and South Sicily; probands homozygotes for 35delG or presenting a T/T genotype are more apt to have a severe-to-profound HL.

Auditory dyssynchrony or auditory neuropathy: understanding the pathophysiology and exploring methods of treatment

OBJECTIVE

To review the literature on auditory dyssynchrony (AD) or neuropathy which is characterized by absent auditory brainstem responses, normal otoacoustic emissions, and word discrimination disproportional to the pure tone audiogram.

RESULTS

Several papers attempt to estimate the prevalence of AD that seems to range between 0.23 and 2% in infants "at risk" for hearing impairment and it is considered to be responsible for approximately 8% of newly diagnosed cases of hearing loss in children per year. The prevalence gets even higher, reaching 10% in children with permanent hearing loss. It seems that AD is not a single disease but a spectrum of pathologies that affect the auditory pathway at the level of the inner hair cells, the synapses, or the auditory nerve. Many predisposing or contribution factors have been reported, including prematurity, hyperbilirubinemia, hypoxia, low-birth weight, immunological conditions, infectious diseases, etc. Before proposing any method of management, parents should be informed about the variation among patients and the changes that may appear in some children's audition over time. Sigh language, speech and language therapy, hearing-aids, and cochlear implantation have been used in the treatment of AD. In general, AD is rather refractory to conventional amplification and cochlear implantation has been found an effective method of management in young implanted children with severe/profound deafness and AD. However, the situation is more complicated and challenging in milder hearing losses.

CONCLUSION

The selected and proposed 30 related articles published in the International Journal of Pediatric Otorhinolaryngology aim to stimulate the related research in order to further explore the etiology, pathophysiology, and management of AD.

Evaluation of very low birth weight (≤ 1,500 g) as a risk indicator for sensorineural hearing loss

INTRODUCTION AND OBJECTIVE

Hearing plays an essential role in the acquisition, development and maintenance of the properties of the speech and language. Birth weight is an indicator of biological maturation of the newborn. Premature newborns with very low birth weight (VLBW<1,500 g) constitute a group with the highest risk of sensorineural hearing loss. Our objective was to ascertain the degree of hearing loss, sensorineural hearing loss and presence of the association to other risk factors for hearing loss in VLBW infants included in the Universal Hearing Loss Screening Programme at the University Mother-Child Hospital of Gran Canaria (Spain) in the 2007-2010 period.

MATERIAL AND METHODS

This was a retrospective study of 364 infants with VLBW, measured by transient evoked otoacoustic emissions and auditory brainstem response.

RESULTS

There were 112 newborn (30.8%) referred for auditory brainstem response. A diagnosis of hearing loss was given to 22 newborns (2.2%), 14 had conductive hearing loss and 8, sensorineural hearing loss (SNHL), of which 2 had bilateral profound hearing loss. The VLBW newborn presented the association to another risk factor in more than a quarter of the sample studied. All those diagnosed with SNHL were premature.

CONCLUSIONS

The percentage of VLBW newborns diagnosed with hearing loss is higher than expected in the general population. All those diagnosed with SNHL were premature and presented one or 2 hearing risk factors associated with VLBW.

Speech perception outcomes after cochlear implantation in prelingually deaf infants: the Western Sicily experience

OBJECTIVES

To describe audiometric characteristics and speech perception performances of prelingually deaf Sicilian children after cochlear implantation; to identify the influence of cochlear implant (CI) user and family's characteristics on speech recognition and intelligibility outcomes.

METHODS

Twenty-eight infants with a congenital or acquired hearing impairment and implanted before the 3rd year of life were studied; all children suffered from bilateral sensorineural hearing loss (SNHL) with evidence of lack of hearing aids benefit and no evidence of intellectual disability. The study of the main characteristics associated with CI user and family's profile was performed with a clinical assessment including pre-implant and post-implant (1, 3, 6, 12 and 18 months) behavioural audiometry (evaluating average threshold for the frequencies 0.5, 1, 2 and 4KHz) and speech recognition tests (IT-MAIS, MUSS, CAP and SIR).

RESULTS

Our cohort was characterized by an early diagnosis of SNHL (5.77 and 12.17 months for congenital and acquired HL respectively), a short length of deafness (average=6.78 months) and an implantation before the 3rd year of life (mean=24.25 months; range from 10 to 36). Analysis of audiometric threshold revealed a significantly improved capacity to detect sounds within the conversational speech spectrum after 12 months from implantation (r=0.99; p<0.001). The main speech recognition test evidenced speech perception and speech intelligibility performances (CAP median value of 3; SIR category=3 in 46.42%) equal to those children with same characteristics reported by literature. With the exception of 'daily CI use' (p<0.001), none of the variables associated with CI user and family's profile resulted significant predictor of speech perception improvement.

CONCLUSIONS

This work demonstrates that all children of our cohort, with an early diagnosis of SNHL and a CI surgery performed before the 3rd year of life, presented a progressive audiometric and speech improvement through the first 12-18 months after cochlear implantation. The study also highlights that, differently from the others variables studied, a continuous CI use influences significantly speech perception and recognition outcomes.

Prelingual sensorineural hearing loss and infants at risk: Western Sicily report

OBJECTIVE

To evaluate independent etiologic factor associated with sensorineural hearing loss (SNHL) in newborn at risk; to study the role of their interaction especially in NICU infants who present often multiple risk factors for SNHL.

METHODS

The main risk factors for SNHL reported by JCIH 2007 were evaluated on 508 infant at risk ranging from 4 to 20 weeks of life, transferred to the Audiology Department of Palermo from the main births centers of Western Sicily. After a global audiological assessment, performed with TEOAE, tympanometry and ABR, the prevalence and the effect of risk factors was statistically studied through univariate and multivariate analysis on the total population (normal and deaf subjects).

RESULTS

Fifty-one infants (10.03%) were diagnosed with SNHL (45 bilateral and 6 monolateral) with a mean hearing threshold of 87.39 ± 28.25 dB HL; from logistic regression analysis family history of hearing impairment (HI) and TORCH infections resulted independent significant risk factors (P<0.00001 and P=0.024 respectively). High SNHL percentages were evidenced also in NICU babies, due to the various pathologies and risk factors presented by these infants, and among newborns who suffered from hyperbilirubinemia requiring exchange transfusion (11.97% and 9.52% respectively). Craniofacial abnormalities (CFA) and syndromes associated to HI showed an important relationship (P<0.00001) with conductive hearing loss (CHL). Multiple regression analysis of the variation in SNHL among NICU infants evidenced an increased risk for SNHL of 21.24% and of 19.33% respectively in preterm infants and in case of hyperbilirubinemia if respiratory distress is concomitant with these risk factors. It was also observed an higher risk of SNHL (99.66%) in case of coexistence of prematurity and hyperbilirubinemia. Finally among infants with very low birth weight (VLBW) it was evidenced a statistically difference between the mean weight of SNHL infants respect to NHL newborns (P=0.048).

CONCLUSION

The high SNHL prevalence (10.03%) in our cohort underlines how infants at risk are more susceptible to suffer from SNHL; in particular NICU newborns have a 33% greater chance of developing SNHL, because of the presence of multiple risk factors (or=1.33) and their interaction. As the number of coexisting risk factors increases, the prevalence of SNHL also increases (r(2)=0.93).