Changes in the hearing thresholds of infants who failed the newborn hearing screening test and in infants treated in the neonatal intensive care unit

Hearing Loss and Risk Factors in Very Low Birth Weight Infants

The incidence of sensorineural hearing loss (SNHL) is still high in very low birth weight (VLBW) infants. The purpose of our study was to provide the prevalence rates of SNHL and to analyze the risk factors of hearing impairment and changes in hearing thresholds in a cohort of VLBW infants. A retrospective observational study was conducted in our neonatal intensive care unit (NICU) from 2012 to 2016. All VLBW infants included were screened by transient evoked otoacoustic emissions (TEOAEs) and diagnostic auditory brainstem response (ABR). In total, we enrolled 316 infants and SNHL was diagnosed in 68, leading to an early incidence of 21.5% as 36 infants out of 68 improved. Finally, SNHL was confirmed in 20 patients (6.3%) who needed hearing aids. They were significantly smaller, sicker, had longer hospitalizations, and received more ototoxic therapies. Logistic regression analysis showed that gestational age (GA) influenced the association between drugs and SNHL. The results underlined how the total exposure to antibiotics is significantly associated with SNHL, even after GA correction. In conclusion, GA, birth weight and, above all, the length and complexity of NICU stay quantify the risk of SNHL and should be considered at the individual level for parent counseling.

Hearing Outcomes in the Audiology Department of a Children Hospital

The incidence of sensorineural hearing loss is between 1 and 3 per 1000 in healthy neonates and 2-4 per 100 in high-risk infants. In this study, we assessed the incidence of hearing impairment in normal term (≥ 37 wga) infants (control group), in children with suspicion and/or risk factors of hearing loss, included premature infants (< 37 weeks gestational age (wga) and/or low birth weight < 2,5 Kgr), in children diagnosed with a specific syndrome and in children with speech disorder, candidate for speech therapy. Hearing impairment is a severe consequence of prematurity and its prevalence is inversely related to the maturity of the baby based on gestation age and /or birth weight. Both above parameters are of particular importance and it has not been found that one factor prevails over the other. Premature infants have many concomitant risk factors for hearing impairment. The most important other risk factors were ototoxic medications, very low birth weight and "treatment in the intensive care unit '' (low Apgar score and mechanical ventilation). Frequent risk factors such as congenital infections and family history of hearing loss, although frequently recorded, does not seem to be very significant. Children with speech disorder do not seem to suffer from hearing impairment more frequently than children in general population.

Risk Factors for Sensorineural Hearing Loss and Auditory Maturation in Children Admitted to Neonatal Intensive Care Units: Who Recovered?

Background: Newborns admitted to neonatal intensive care units (NICUs) are at higher risk of developing sensorineural hearing loss (SNHL), which may improve over time. The aim of this study was to describe the prevalence of the main risk factors for SNHL in a NICU cohort, focusing on children who underwent auditory maturation. Methods: An observational study of 378 children admitted to NICUs, who were followed for at least 18 months, with periodic audiologic assessments. Results: Out of 378 patients, 338 had normal hearing and 40 were hearing-impaired; we found a higher percentage of extremely preterm (EPT) and extremely low-birthweight (ELBW) infants in SNHL children (p < 0.05). Seventeen infants presented auditory improvement, with a mean maturation time of 6.17 months. A significant difference emerged between patients with stable SNHL and those who improved only in the case of hyperbilirubinemia (p = 0.005). The initial hearing threshold was a predictor of auditory improvement and moderately correlated to the time of auditory maturation (p = 0.02). Conclusions: Our study supports the trend toward recognizing worse prognoses and slower maturation processes among NICU children who suffer from severe to profound SNHL. Caution must be taken when deciding on earlier cochlear implantation.

An Economic Evaluation of Australia's Newborn Hearing Screening Program: A Within-Study Cost-Effectiveness Analysis

OBJECTIVES

Hearing loss is one of the most prevalent congenital disorders among children. Many countries have implemented universal newborn hearing screening (UNHS) for the early diagnosis and treatment of hearing loss. Despite widespread implementation, the value for money of UNHS is unclear due to lack of cost and outcomes data from rigorous study designs. The objective of this research is to conduct a within-study cost-effectiveness analysis of UNHS compared with targeted screening (targeting children with risk factors of hearing loss) from the Australian healthcare system perspective. This evaluation is the first economic evaluation to assess the cost-effectiveness of UNHS compared to targeted screening using real-world data from a natural experiment.

DESIGN

The evaluation assumed the Australian healthcare system perspective and considered a time horizon of 5 years. Utilities were estimated using responses to the Health Utilities Index Mark III. Screening costs were estimated based on the Victorian Infant Hearing Screening Program. Ongoing costs were estimated based on administrative data, while external data sources were used to estimate costs related to hearing services. Missing data were handled using the multiple imputation method. Outcome measures included quality-adjusted life years (QALYs) and four language and communication-related outcomes: Peabody Picture Vocabulary Test, Wechsler Nonverbal Scale of Ability, Progressive Achievement Test, and comprehensive, expressive, and total language scores based on the Preschool Language Scale.

RESULTS

On average, the UNHS cost an extra Australian dollar (A$)22,000 per diagnosed child and was associated with 0.45 more QALYs per diagnosed child compared with targeted screening to 5 years, resulting in an incremental cost-effectiveness ratio (ICER) of A$48,000 per QALY gained. The ICERs for language outcomes lay between A$3,900 (for expressive language score) and A$83,500 per one-point improvement in language score (for Wechsler Nonverbal Scale of Ability). UNHS had a 69% probability of being more cost-effective compared to targeted screening at a willingness to pay threshold of A$60,000 per QALY gained. ICERs were most sensitive to the screening costs.

CONCLUSIONS

The evaluation demonstrated the usefulness of a within-study economic evaluation to understand the value for money of the UNHS program in the Australian context. Findings from this evaluation suggested that screening costs were the key driver of cost-effectiveness results. Most outcomes were not significantly different between UNHS and targeted screening groups. The ICER may be overestimated due to the short follow-up period. Further research is warranted to include long-term resource use and outcome data, late diagnosis, transition and remission between severity levels, and timing of diagnosis and treatment.

The duration of intrauterine development influences discrimination of speech prosody in infants

Auditory speech discrimination is essential for normal language development. Children born preterm are at greater risk of language developmental delays. Using functional near-infrared spectroscopy at term-equivalent age, the present study investigated early discrimination of speech prosody in 62 neonates born between week 23 and 41 of gestational age (GA). We found a significant positive correlation between GA at birth and neural discrimination of forward versus backward speech at term-equivalent age. Cluster analysis identified a critical threshold at around week 32 of GA, pointing out the existence of subgroups. Infants born before week 32 of GA exhibited a significantly different pattern of hemodynamic response to speech stimuli compared to infants born at or after week 32 of GA. Thus, children born before the GA of 32 weeks are especially vulnerable to early speech discrimination deficits. To support their early language development, we therefore suggest a close follow-up and additional speech and language therapy especially in the group of children born before week 32 of GA.

Newborn hearing screening programme based on an integrated hospital and community care system. Results of the first 4 years of activity

Since January 2012, babies born in the province of Modena, Italy, have routinely undergone hearing testing as part of a two-stage screening programme. Newborn hearing screening (NHS) has been based on an integrated hospital and community care system and this study aims to assess screening coverage, referral rates, the prevalence, type and extent of hearing loss several years into the programme. Data were collected from January 1, 2012 to December 31, 2015. Coverage was over 99% in all five facilities of the province. The ratio of "fails of the screening" to the total number of infants tested varied over the period from 1.2% to 0.9% in the third level facility, and from 0.8% to 0.4% in the other four. Although hearing loss was mainly associated with dysmorphic\syndromic diseases or a family history of hearing loss, some 23% of cases were identified with no known risk factors. We highlight the importance of the NHSP and the need for strong support from healthcare administrators to ensure high coverage. This is especially true since although the prevalence of hearing loss was higher among infants with audiological risk factors, several cases of hearing loss were found in newborns with no known risk factors.

The Correlation Between Click-Evoked Auditory Brainstem Responses and Future Behavioral Thresholds Determined Using Universal Newborn Hearing Screening

This retrospective study was undertaken to assess the correlation between click-evoked auditory brainstem responses and behavioral hearing tests. We recruited a total of 16646 infants born in Ditmanson Medical Foundation Chia-Yi Christian Hospital, Taiwan, from 2012 to 2018 for such assessment purpose. Their data including the click-evoked auditory brainstem response (ABR), referral, and diagnostic follow-up were collected. Spearman correlation method was employed to assess the relationship between ABR and pure-tone threshold. The correlation between the click-evoked ABR that met the National Health Administration standards and the click-evoked ABR derived from estimates before and after the 2.5 years of age effectively predicted the toddlers' pure-tone audiometry (PTA) thresholds at 2-4 kHz.

Monitoring of the auditory pathway maturation after early intervention during the first year of life in infants with sensorineural hearing loss

Purpose

The objective of this study was to investigate the auditory pathway maturation monitored by auditory brainstem responses (ABR) in infants with hearing loss during the first year of life. ABR were used to estimate hearing thresholds and the effect of early intervention strategies using hearing aids (HA).

Methods

Click-evoked ABRs were measured in 102 infants aged from 0 to 12 months to determine their individual auditory threshold. Early therapy intervention was recommended before 12 months of age and analyzed. To evaluate the effect of hearing amplification on auditory maturation, different subgroups of infants with moderate hearing loss were analyzed and the auditory pathway maturation was determined based on IPL I–V shortening.

Results

Overall, 110 ears (54.0% of 204 ears) with mild to profound HL showed threshold changes of 10 dB up to 60 dB in the follow-up ABR testing. HA were prescribed at the age of 3.8 ± 3.9 months. Cochlear implantation (CI) was performed in cases of repeated profound HL at the age of 9.9 months ± 4.5 months. A significant shortening of IPL I–V in all subgroups of infants (with and without risk factors) who received HA was shown and assumed auditory pathway maturation.

Conclusion

An early intervention using optimally fitted HA influenced auditory pathway maturation and may lead to improvements of hearing thresholds during the first year of life in infants. This study underscores the importance of not only providing HAs to infants, but also controlling for hearing threshold changes ensuring that HAs provide the optimal level of intervention or CI is indicated.

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.

Newborn hearing screening results: Comparison of Syrian and Turkish newborns; factors influencing the difference

OBJECTIVES

This study aimed to compare the hearing screening results of Syrian and Turkish newborns and reveal the risk factors faced by Syrian refugees.

METHODS

The neonatal hearing screening results of newborns born in, or admitted to, the Sanliurfa Research and Education Hospital, Sanliurfa/Turkey, between January 01, 2018, and December 31, 2018, were analyzed. Newborns with congenital anomalies and syndromes were excluded from the study. Also, the neonatal hearing screening results and risk factors of newborns diagnosed with hearing loss were analyzed.

RESULTS

A total of 6034 Syrian and 37,219 Turkish newborns were included in the study. Hearing loss was found in 84 (0.2%) of 37,219 Turkish newborns and 26 (0.4%) of 6034 Syrian newborns. In this study, the risk factors such as consanguineous marriages, familial hearing loss, hospitalization in intensive care, prematurity, low birth weight (less than 1500 g), hyperbilirubinemia, use of ototoxic drugs, history of congenital infection, blood incompatibility, and trauma at birth were found in newborns with hearing loss. The risk factors were present in 41.7% of Turkish newborns and 65.4% of Syrian newborns with hearing loss.

CONCLUSIONS

The high hearing loss rates found in Syrian newborns showed how accurate it was to include the Syrian migrants born in Turkey into the neonatal hearing screening program and the newborns with hearing loss into appropriate rehabilitation programs. Further studies should focus on the risk factors faced by Syrian migrants so that the number of Syrian newborns with hearing loss can be reduced.

Hearing loss in very preterm infants: should we wait or treat?

This study investigated hearing threshold changes during the first year of corrected age (CA) in infants admitted in a neonatal intensive care unit (NICU). In 5 years, 239 infants with birth weight (BW) ≤ 1,000 gm and/or gestational age (GA) ≤ 30 weeks were enrolled. Hearing was evaluated by oto-acoustic emission (OAEs) before discharge and auditory brainstem response (ABR) within 3 months of CA. Infants affected by unilateral or bilateral hearing loss were addressed to audiological follow-up until definitive diagnosis (within 6 months of CA). Changes in hearing threshold were also carefully analysed. 207 (86.6%) infants had normal hearing while 32 infants (13.4%) showed hearing loss (HL) at the confirmative ABR evaluation (9 mild, 16 moderate, 4 severe, 3 profound). The latter showed lower GA (27.7 ± 2 vs 28.4 ± 1.2; p = 0.0061) and BW (950 ± 390 vs 1,119 ± 326 gm; p = 0.0085). At final evaluation, 15 infants (47%) recovered a normal hearing. HL was confirmed in 17 patients. Among these, 3 infants were addressed to audiological follow-up (one case of mild unilateral hearing loss (UHL) and two with moderate UHL), while in 14 cases (44%) with bilateral sensory neural hearing loss (SNHL) (7 moderate, 4 severe, 3 profound) hearing aids were prescribed. They showed significantly lower GA and longer hospital stay in the NICU in comparison with infants without indication for audiological habilitation (18 infants) (GA 26.2 ± 2.2 weeks vs 28.4 ± 2.4; p = 0.01; NICU stay 132 ± 67 vs 59 ± 7; p = 0.0002). Definitive diagnosis was obtained at 5.9 ± 1.3 months of CA. Our study confirms the importance of audiological surveillance in preterm newborns. Hearing thresholds of preterm infants with hearing loss can change during the first year of CA and we observed normalisation in 47% of our patients. Most vulnerable to permanent SNHL were very preterm infants with a longer NICU stay, while a shorter stay represents a favourable prognostic factor for hearing improvement.

Hearing screening outcome in neonatal intensive care unit graduates from a tertiary care centre in Singapore

BACKGROUND

We aimed to analyse the outcome of universal newborn hearing screening (UNHS) and high-risk hearing screening in neonatal intensive care unit (NICU) graduates in a tertiary care unit.

METHODS

The hearing screen programme comprises a 2-stage automated auditory brainstem response protocol followed by a high-risk hearing screen at 3-6 months. This study is a retrospective study of NICU graduates born between April 2002 and December 2009. Data on hearing screening, audiological assessment, and management were extracted from a computerized data management system (HITRACK).

RESULTS

Of 100,225 newborn infants, 2.9% were admitted to the NICU during the study period. The overall incidence of hearing loss (HL) of any type/severity was 35/1,000 infants. Of infants with HL, 92.4% had their first automated auditory brainstem response at/before 1 month of corrected age. The incidence of congenital permanent HL identified by the UNHS was 15.4/1,000. The corrected median age of diagnosis was 4.5 months (1-23.5 months). Of 2,552 NICU graduates who passed the UNHS, 75.5% were retested at 3-6 months of life. Twelve infants with permanent late-onset HL were identified, raising the overall incidence of permanent HL to 19.9/1,000; 1.1/1,000 had auditory neuropathy. Of the 92 infants with HL, 89 (96.7%) had multiple risk factors.

CONCLUSIONS

There is a high incidence of HL in NICU graduates; 22.6% were late in onset. An early rescreen in those who pass the UNHS is a beneficial step for this high risk population.

Early Treatment with Growth Hormone (GH) and Rehabilitation Recovers Hearing in a Child with Cerebral Palsy

Neonatal hearing loss is one of the most common anomalies and is frequently associated with delivery problems. The effects of growth hormone (GH) on brain regeneration after an injury are well known. This paper looks at a male child diagnosed with cerebral palsy, psychomotor affectation, left spastic hemiparesis, and bilateral sensorineural hearing loss after fetal distress due to ruptured membranes before the delivery of more than 30 hours of evolution and several episodes of severe hypoglycemia. From 3.5 months of age, we treated him with GH (0.04 mg/kg/day), Melatonin (5 mg/day and 6 months later 10 mg/day) and rehabilitation, for a period of 14 months; at discharge, the child fully recovered all the disabilities produced by his cerebral palsy, including normal hearing; GMFM-88 increased from 7.84% to 48.23%; Battelle scores increased from 2 to 9 after 7 months of treatment, and to 30, 1 year after discharge. Most likely hearing loss was recovered due to the effect of GH on the production of hair cells from stem cells (only present in very young children) in the cochlear sensory epithelium. This is the first case of recovery of hearing loss in humans after GH administration. Moreover, GH administration is useful and safe for early treatment of cerebral palsy.

Prevalence of Hearing Impairment Among High-Risk Newborns in Ibadan, Nigeria

The burden of severe hearing impairment is increasing with two-thirds of these hearing impaired people residing in developing countries. Newborn hearing screening helps to identify early, babies who need intervention in order to prevent future disability. Neither universal nor targeted hearing screening programme is available in Nigeria. Objectives: This study was carried out to assess the prevalence of hearing impairment among high-risk newborns in UCH and the associated risk factors. Materials and Methods: Two hundred one newborns in the neonatal unit of UCH with risk factors for hearing impairment had hearing screening done using automated auditory brainstem response (AABR) at 30, 45, and 70 dB at admission and discharge, and those that failed screening at discharge were rescreened at 6 weeks post-discharge. Results: Eighty-three (41.3%) and 32 (15.9%) high-risk newborns failed at admission and discharge screening respectively, and 19 (9.5%) still failed at follow up screening. The majority of hearing loss at follow up was bilateral (94.7%) and severe (52.6%). The risk factors associated with persistent hearing loss at follow up were acute bilirubin encephalopathy (RR = 11.2, CI: 1.4-90.6), IVH (RR = 8.8, CI: 1.1-71.8), meningitis (RR = 4.8, CI: 1.01-29), recurrent apnoea (RR = 2.7, CI: 1.01-7.3), severe perinatal asphyxia NNE III (RR = 7, CI: 2.4-20.2). Conclusion: Severe and bilateral hearing impairment is a common complication among high risk newborns in UCH persisting till 6 weeks post-neonatal care. Severe perinatal asphyxia with NNE III, ABE, IVH, meningitis and administration of amikacin for more than 5 days were significant risk factors. We recommend that SCBU graduates with these risk factors should have mandatory audiologic evaluation at discharge.

Threshold changes of ABR results in toddlers and children

INTRODUCTION

Auditory brainstem response (ABR) is a clinically established method to identify the hearing threshold in young children and is regularly performed after hearing screening has failed. Some studies have shown that, after the first diagnosis of hearing impairment in ABR, further development takes place in a spectrum between progression of hearing loss and, surprisingly, hearing improvement.

OBJECTIVE

The aim of this study is to evaluate changes over time of auditory thresholds measured by ABR among young children.

MATERIAL AND METHODS

For this retrospective study, 459 auditory brainstem measurements were performed and analyzed between 2010 and 2014. Hearing loss was detected and assessed according to national guidelines. 104 right ears and 101 left ears of 116 children aged between 0 and 3 years with multiple ABR measurements were included. The auditory threshold was identified using click and/or NB-chirp-stimuli in natural sleep or in general anesthesia. The frequency of differences of at least more than 10dB between the measurements was identified.

RESULTS

In 37 (35%) measurements of right ears and 38 (38%) of left ears there was an improvement of the auditory threshold of more than 10dB; in 27 of those measurements more than 20dB improvement was found. Deterioration was seen in 12% of the right ears and 10% of the left ears. Only half of the children had stable hearing thresholds in repeated measurements. The time between the measurements was on average 5 months (0 to 31 months).

CONCLUSION

Hearing threshold changes are often seen in repeated ABR measurements. Therefore multiple measurements are necessary when ABR yields abnormal. Hearing threshold changes should be taken into account for hearing aid provision.

Comparison of maturational process of hearing threshold in early life between at-risk and low-risk preterm infants

AIM

To detect any abnormality in the maturational process of hearing threshold during the early life in at-risk preterm infants.

STUDY DESIGN

The threshold of brainstem auditory evoked response was recorded and analyzed longitudinally from 30 to 42weeks of postconceptional age in 357 at-risk infants born at 23-36weeks of gestation. The results were compared with those in 82 low-risk infants born at 30-42weeks at various postconceptional ages.

RESULTS

From 31 to 42weeks, the response threshold in the at-risk infants was consistently slightly higher than that in the low-risk infants. No statistically significant difference was found between the two groups of infants at any designated postconceptional ages. The threshold in the at-risk infants born at 23-29weeks of gestation tended to be higher than those born at 30-36weeks at various postconceptional ages, but the difference did not reach statistical significance. There was also no significant difference in the slope of BAER threshold-age function between the at-risk infants, irrespective of gestational ages, and the low-risk infants.

CONCLUSION

During the early life, hearing threshold in at-risk preterm, mainly very preterm, infants is marginally elevated, but the maturational process of the threshold is generally similar to that in low-risk infants, without notable abnormality.

Is very early hearing assessment always reliable in selecting patients for cochlear implants? A case series study

INTRODUCTION

This study concerns a case series of 23 infants with a diagnosis of severe-to-profound hearing loss at 3 months old, who significantly improved (even reaching a normal auditory threshold) within their first year of life.

METHODS

All infants were routinely followed up with audiological tests every 2 months after being fitted with hearing aids as necessary. A reliable consistency between the various test findings (DPOAE, ABR, behavioral responses, CAEP and ECoG) clearly emerged in most cases during the follow-up, albeit at different times after birth.

RESULTS

The series of infants included 7 cases of severe prematurity, 6 of cerebral or complex syndromic malformations, 5 healthy infants, 2 with asymptomatic congenital CMV infection, and 1 case each of hyperbilirubinemia, hypoxia, and sepsis. All term-born infants showed a significant improvement over their initial hearing threshold by 6 months of age, while in most of those born prematurely the first signs of threshold amelioration occurred beyond 70 weeks of gestational age, and even beyond 85 weeks in one case.

CONCLUSIONS

Cochlear implantation (CI) should only be considered after a period of auditory stimulation and follow-up with electrophysiological and behavioral tests, and an accurate analysis of their correlation. In our opinion, CI can be performed after a period of 8 months in all term-born infants with persistent severe-to-profound hearing loss without risk of diagnostic error, whereas the follow-up for severely preterm infants should extend to at least 80 weeks of gestational age.

Changes in hearing threshold between 28 and 42 weeks of age in babies born at under 30 weeks of gestation

AIM

This study aimed to describe changes in hearing thresholds in babies born below 30 weeks of gestation at 28-42 weeks of postconceptional age, detect differences between gestational ages and explore the prevalence of hearing impairment.

METHODS

The threshold of brainstem auditory evoked response (BAER) was obtained longitudinally at 28-42 weeks of postconceptional age in 71 babies born at 23-29 weeks of gestation.

RESULTS

The BAER threshold was 28 decibels above normal hearing level (dB nHL) at 28 weeks of postconceptional age and decreased to 13 dB nHL at 39-42 weeks. The threshold was slightly higher in babies born at 23-26 weeks of gestation than in those born at 27-29 weeks at most postconceptional ages studied. From 28 to 36 weeks, the threshold decreased at 0.98 dB/week. At term, BAER threshold elevation (>20 dB nHL) occurred in 12 (16.9%) of the 71 babies.

CONCLUSION

The hearing threshold of babies born at 23-29 weeks of gestation decreased from 28 dB at 28 weeks of postconceptional age to 13 dB at 42 weeks. There were no major differences between gestational ages. During the preterm period, the threshold changed at around 1 dB/week. At term, one in six babies had hearing impairment.

Comparison of auditory brainstem response in HIV-1 exposed and unexposed newborns and correlation with the maternal viral load and CD4+ cell counts

OBJECTIVE

The effects of maternal HIV infection and antiretroviral therapy on hearing of HIV-exposed newborns in sub-Saharan Africa have not been investigated. We determined the prevalence of sensorineural hearing loss among HIV-exposed newborns and the association between the hearing threshold and maternal and newborn parameters.

DESIGN

A cohort audiometric study of newborns between October 2012 and April 2013.

SETTINGS

A secondary and tertiary hospital-based study.

PARTICIPANTS

Consecutive 126 HIV-exposed and 121 HIV-unexposed newborns.

INTERVENTION

Hearing screening of the newborns was done with Auditory Brainstem Response and compared with maternal HAART, CD4 cell counts, RNA viral loads and newborn CD4 cell count percentage.

MAIN OUTCOME MEASURE

Hearing threshold levels of both groups were measured and analysed.

RESULTS

Around 11.1% of HIV-exposed and 6.6% of unexposed newborns had hearing impairment (P = 0.2214). About 6.4% of HIV-exposed and 2.5% HIV-unexposed newborns had hearing threshold of more than 20 dBHL (P = 0.1578). There was no significant association between the hearing thresholds of HIV-exposed newborns and maternal CD4 cell counts (P = 0.059) but there was with maternal viral load (P = 0.034). There was significant difference between the hearing thresholds of HIV-exposed newborns with CD4% of 25 or less and more than 25. This study showed significant difference in the hearing of the 119 HAART-exposed newborns and seven unexposed newborns [P = 0.002; risk ratio, 0.13 (0.05-0.32)].

CONCLUSION

There was a trend towards more hearing loss in HIV-exposed newborns. However, hearing thresholds increase with increasing mothers' viral load. The background information supports the need for further studies on the role of in-utero exposure to HIV and HAART in newborn hearing loss.

Newborn hearing screening and early diagnostic in the NICU

The aim was to describe the outcome of neonatal hearing screening (NHS) and audiological diagnosis in neonates in the NICU. The sample was divided into Group I: neonates who underwent NHS in one step and Group II: neonates who underwent a test and retest NHS. NHS procedure was automated auditory brainstem response. NHS was performed in 82.1% of surviving neonates. For GI, referral rate was 18.6% and false-positive was 62.2% (normal hearing in the diagnostic stage). In GII, with retest, referral rate dropped to 4.1% and false-positive to 12.5%. Sensorineural hearing loss was found in 13.2% of infants and conductive in 26.4% of cases. There was one case of auditory neuropathy spectrum (1.9%). Dropout rate in whole process was 21.7% for GI and 24.03% for GII. We concluded that it was not possible to perform universal NHS in the studied sample or, in many cases, to apply it within the first month of life. Retest reduced failure and false-positive rate and did not increase evasion, indicating that it is a recommendable step in NHS programs in the NICU. The incidence of hearing loss was 2.9%, considering sensorineural hearing loss (0.91%), conductive (1.83%) and auditory neuropathy spectrum (0.19%).