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International Journal of Pediatric Otorhinolaryngology 73 (2009) 16911695

Contents lists available at ScienceDirect

International Journal of Pedi

journa l homepage: www.e l1. Introduction

In the general population, 1 newborn every 5001000 birthspresents permanent hearing impairment [1], a greater incidencethan the incidence of diseases routinely screened at birth [2]. Incertain higher risk populations, this incidence could increase10- to 50-fold [1].

A disease must fulll certain requirements before it issystematically screened at birth: high incidence; serious disease(life or function threatening); and existence of an acceptedtreatment which improves the prognosis [3]. Thus, in France,

congenital hypothyroidism (1/4000 births), phenylketonuria (1/15,000), congenital adrenal hyperplasia (1/12,000), drepanocytosis(1/4000), and cystic brosis (1/4000) have been routinely screenedat birth for many years, despite lesser frequency than permanenthearing loss [1].

The risk factors of hearing loss in neonates, which were rstdocumented in 1994 and then revised in 2000 by the JointCommittee on Infant Hearing (JCIH) [4], are: premature birth(gestational age34 weeks); low birth weight (

Hearing impaired children present delays in language learningand general development [7], which could only have beenprevented by early diagnosis and management; while ears aremature at birth, auditory cortex and neural connections onlydevelop with acoustic stimuli [8].

A number of Universal Newborn Hearing Screenings (UNHS)have recently been put in place in France and abroad [9] with goodresults: increased verbal reasoning skills and language werenoticed when children were diagnosed and rehabilitated beforethe age of 12 months [7,8,10].

Hearing screening (based on auditory brainstem response(ABR) and behavioral audiometry) on infants at risk has beenperformed for some time at the University Hospital of Besancon. InApril 2001, we began a new method of screening based on theassociation of automated oto-acoustic emissions (AOAE) and ABR,which optimize the management of hearing impaired children.

While we were reviewing the outcomes of this type ofscreening, the French National Consultative Committee for lifeand health sciences (Comite consultatif national dethique pour les

If the second AOAE testwas positive for one or both ears, ABRwasperformed within 4 weeks (during hospitalisation or afterdischarge in an outpatient clinic).

If thresholds were abnormal on ABR (i.e.: superior to 40 dBHL),the child and his parents were sent to an ENT doctor specialized inchild hearing loss for diagnosis conrmation and management.

AOAE were tested during infants natural sleep (still in theirbed) by qualied bio-medical staff using an Echoscreen1 with a20 s time response. For presence of AOAE the response was PASS,and FLACK when absent. If ABR was performed while infants werestill hospitalised, the same realisation conditions applied. If aninfant had previously been discharged, ABR took place within theaudiology laboratory of the ENT ward. All tests were performed bythe same staff.

During a childs hospitalisation the parentswere approached bypediatricians and the bio-medical staff who offered information onthe risks of newborn permanent hearing loss and discussedscreening tests which were then performed, unless parentsrefused.

C. Ohl et al. / International Journal of Pediatric Otorhinolaryngology 73 (2009) 169116951692sciences de la vie et de la sante) issued a statement, which,although skeptical on UNSH, is, however, supportive of screeninginfants at risk [11].

2. Materials and methods

The selected population included every newborn presentingone or more of the risk factors dened by the JCIH [4]: prematurebirth (gestational age 34 weeks); low birth weight (

Sixty children (i.e. 4.55% of the children who went through theentire three-step screening process) were diagnosed with hearingloss, 46 of whom were diagnosed with sensorineural hearing loss(Table 1). If we extrapolate these results to the children lost to

are diagnosed and rehabilitated earlier, show better language and

Table 1Characteristics of the hearing impairment screened.

Hearing loss CHL SNHL

Unilateral Bilateral Total Unilateral Bilateral Total

Medium 6 6 12 9 23 32

Severe 2 0 2 2 2 4

Profound 0 0 0 1 9 10

Total 8 6 14 12 34 46

SNHL: sensorineural hearing loss; CHL: conductive hearing loss.

L

=14)

Unilateral SNHL

(n=12)

Bilateral SNHL

(n=34)

p

Table 3Risk factors comparison between sensorineural hearing loss and normal hearing

infants.

NH and CHL

(n=1273)

SNHL

(n=46)

p

Severe birth asphyxia 12 (0.9%) 4 (8.7%) 2103Neurological disorders 9 (0.7%) 6 (13.0%) 5106Syndromes associated

with hearing loss

9 (0.7%) 4 (8.7%) 7104

Craniofacial anomalies 18 (1.4%) 2 (4.3%) 0.15

Family deafness 14 (1.1%) 3 (6.5%) 0.02

TORCH 6 (0.5%) 4 (8.7%) 2104

Number of risk factors

0 343 (26.9%) 9 (19.6%)

C. Ohl et al. / International Journal of Pediatric Otorhinolaryngology 73 (2009) 169116951694better behavioral skills at the age of 5 than children diagnosed later[7].

In our department, we have performed NHS on infants at risk(as dened by JCIH in 2000) since 2001. Over that time, 4.55% ofscreened children were diagnosed with hearing impairment;similar to the ndings of several other studies on infants at risk[1,5,6,12,13], regardless of the protocol used.

AOAE is the screening test of choice because it is: fast and easyto use at a neonate bed; non-invasive; and highly sensitive andreproducible [14]. The main disadvantage of AOAE, however, isthat it is not capable of detecting retro cochlear deafness to whichnewborns at risk are susceptible (even though its prevalence isrelatively low, at 2.1% of permanent hearing loss in children) [15].As a result, many screenings now include an automated ABR test,from which the referral rate is 3.2% [16]. Such tests are onlymarginally longer and slightly more expensive than AOAE.However, at the time we dened our screening test, automatedABR was not yet available nor had proven its superiority to AOAE.

In this study, the referral rate after the two-step protocol was10%, higher than many studies on universal screenings with AOAEprotocols [12,15,17,18]; however, this type of screening is usuallymeant for bilaterally absent OAE, therefore contributing to lowerreferral rates [12]. However, in studies on infants at risk, thereferral rate with AOAE can increase up to 12% [19] when ABR isperformed as a third step, allowing the identication of falsepositive results in the test (indeed 50% of ABRs were normal).

Among all tested risk factors, severe birth asphyxia, neurolo-gical troubles, syndromes known to associate hearing loss and inutero infection by TORCH, were present (statistically signicant) inall four groups of infants (Table 2) and are a reection of globalhealth. Age at the time of the rst AOAE, also a risk factor forhearing impairment (p < 103), is a further reection of infantsglobal health status, given we had to wait until infants were in astable condition before we could test them.

For children with a family history of permanent childhoodsensorineural hearing loss, the difference between all groups wassignicant, although it was the least signicant risk factor;probably due to its low prevalence in our population (Table 2).Hyperbilirubinemia, however, had too low a prevalence forstatistical analysis.

Concerning craniofacial anomalies, no difference was shownbetween SNHL and the normal hearing group (Table 3), whereasthere was a signicant difference between CHL and the normalhearing group, which is expected as most of the 18 children withcraniofacial anomalies had cleft palate (8) or ear aplasia (3major, 6minor) which imply conductive hearing loss.

Prevalence of birth weight inferior to 1500 g and prematurebirth (34 weeks), which were correlated, was not signicantlydifferent in all four groups of infants, probably due to the highproportion of premature births in the global population (68%). Thiswas also found in other studies [6] and explains why, in thosestudies, the population was recruited only among prematurebirths: to eliminate bias and solely describe the other risk factors[12].

Nevertheless, our results are broadly comparable to resultsfound in the literature [1,46,12,13]; except for the non-signicance of craniofacial anomalies as already mentioned.Prevalence of the different etiologies observed in our study, alsocorroborate what is generally described in older hearing impairedchildren [2022] with the exception of a higher rate of prematureand lowbirthweight infants in our population (most likely a bias ofour neonatal screening, which included all premature newborns)and the high literature rate of congenital rubella (which is notpresent at all in our population). The later is explained bysuccessful rubella vaccination campaigns over the years. Asetiologies remain the same over the years, newborn screeningsseem even more pertinent. Indeed, all causes diagnosed early leadto a better management of impaired hearing children.

The association of more than one risk factor, which is extremelyfrequent (27% of the studied population), also appeared to be anadditional risk factor for hearing loss (8% of hearing impairmentamong children withmore than one risk factor). This nding rarelyappeared in the literature to date [23,24], and if hypothesized wasnever statistically proven, despite appearing here to be a relevantrisk factor (p < 103).

Our study also had a high proportion of children lost to followup (almost 10% of the children tested at least once), which may beexplained by different reasons:

A number of children were transferred to regional hospitals assoon as they were in a stable condition, despite the screeningprotocol being incomplete. It is probable though, that some ofthese children completed the remaining screening protocol, assuggested in the transfer note, however wewere not informed ofthe results.

Lack of information with the parents, who, therefore, were notaware enough of the consequences of SNHL and the benets ofearly management; a contributing factor would be that pediatricand ENT units are not in the same wing of our hospital.

Children discharge earlier than expected, which prevented usfrom completing our screening protocol.

The hearing impaired children who slipped through our screen-ing (potentially 37 children, 2.5%) could have had delayed diagnosisandmanagementasa result. Thisextrapolation iswithin the rangeofthatnotedbyother studies [16,18,2527].However, this rather largeextrapolation, does not take into account further hearing evaluationwhich may have been performed in the discharge hospitals whereadditional care could have been provided.

Newborn hearing screening of infants at risk must however beimproved. This may be achieved by giving better information tostaff in charge of newborns (for example pediatricians andparamedics), who must know the risk factors and the benetchildren can get from early diagnosis and management. Parentsalso need to be better informed, and not only at the time of thescreening, for universal newborn screenings, information shouldideally be given before birth. Finally, babys health records shouldbe more consistently used and appropriately lled in and red byparents and medical staff.

Organization could also be improved by, for example,integrating other screening tests such as Guthrie Test, to locatelost to follow up children.

Several studies also demonstrate that newborn hearing screen-ing does not lead to higher maternal anxiety nor negativelyimpacts motherinfant relationships [27]. Because worse hearingoutcomes are associated with a 2 months after birth delayedscreening, UNHS should be performed on every newborn as earlyas possible, i.e. in maternity hospitals before discharge.

Early hearing screening has already proven benets in verbal orbehavioral skills management of hearing impaired children, butalso has economic benets; a recent study showed that, after 10years, the cost of a UNHS would be lower than the overallmanagement cost of hearing impaired children later diagnosed[16,26].

In 2007, the French health high authority (Haute Autorite deSante) had released a position statement recommending initiationof UNHS programs in hospitals and evaluation of its benets andcosts, acknowledging that hearing impairment is a public healthconcern [8]. In 2008, the French National Consultative Committeefor life and health sciences gave a less positive opinion inconsideration of an alternative ethical approach [11] followingrequests by deaf or hard of hearing adults and psychologists. The

committee emphasized the difference between two categories ofchildren screened: children from normal hearing families, whoseparents are anxious to limit and even restore their childs hearing;and children from hearing impaired families, who do notapproach hearing impairment as a handicap and fear unnecessaryovermedication. The committee also insisted on increasingparents information, which may not have been properly deliveredduring short stays in maternity hospitals. We therefore believe

[2] A.L. Mehl, V. Thomson, Newborn hearing screening: the great omission, Pediatrics101 (1998) E4.

[3] J.M. Wilson, Y.G. Jungner, Principles and practice of mass screening for disease,Bol. Ocina Sanit. Panam. 65 (1968) 281393.

[4] Joint Committee on Infant Hearing, American Academy of Audiology, AmericanAcademy of Pediatrics, American Speech-Language-Hearing Association, Direc-tors of Speech and Hearing Programs in State Health Welfare Agencies, Year 2000position statement: principles and guidelines for early hearing detection andintervention programs, Pediatrics 106 (2000) 798817.

[5] S.E. Kountakis, A. Psidis, C.J. Chang, C.M. Stiernberg, Risk factors associated withhearing loss in neonates, Am. J. Otolaryngol. 18 (1997) 9093.

[6] S. Yoshikawa, K. Ikeda, T. Kudo, T. Kobayashi, The effects of hypoxia, premature

C. Ohl et al. / International Journal of Pediatric Otorhinolaryngology 73 (2009) 16911695 1695parents information should be provided: before birth; as a nation-wide campaign; and probably during birth preparation.

While the committee does not provide supporting evidence, it isconcerned that early screening could have a negative impact onparentinfant relationships, despite scientic studies suggesting thecontrary (i.e. early screening does not alter parentinfant relation-ships) as mentioned earlier. The committee is, however, inagreement with screening infants at risk of hearing impairment.It is obvious to screen and then follow high risk babies until normalhearing is restored or surgery is performed (if required) however,our primary goal must be to expand screening to the generalpopulationwhowouldnototherwisehavebeen tested.Additionally,a UNHS program would enable us to reach those cases wheremedical staff are not or incompletely informedof the risk factors.

5. Conclusion

The incidence of hearing impairment diagnosed following thenewborn screening test, as specied above, is comparable to theincidence rate commonly reported in the literature.

Although the use of AOAE gives satisfying results, since it isreliable and easy to use, we must remain attentive that it does notidentify retro cochlear hearing losses in this at risk population.

The percentage of children lost to follow up is not a result of ourprotocol but, rather, due to a lack of parents and pediatric teamsknowledge of the risk factors leading to hearing loss or impairmentand the benets of early diagnosis and management.

The association of several risk factors, rarelymentioned and notstatistically evidenced in the literature to date, proves here to be asignicant additional risk factor for hearing impairment.

The importance of selective screening for infants at risk isrecognized and supported world-wide. However, we believe suchacceptance should only be taken as a precursor to UniversalNewborn Hearing Screening; this will be achieved by spreadingknowledge of the benets of early intervention and encouragingthe development of structures required to implement such aprotocol.

Acknowledgment

The authors want to express thanks to Anne Chaurand, the bio-medical agent who performed all automated OAE and ABR of thisstudy and lled in meticulously the screening records.

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Newborn hearing screening on infants at riskIntroductionMaterials and methodsResultsDiscussionConclusionAcknowledgmentReferences