Risk Factors and Prognostic Factors of Hearing Impairment in Neonatal Intensive Care Unit-Treated Infants

Risk factors for infant hearing loss: a meta-analysis

Hearing loss is a common disability in infants that significantly impacts their cognitive, language, and literacy development. This study aimed to systematically assess the risk factors for the early identification and intervention in infant hearing loss. Databases were searched for meta-analyses of observational studies until November 2023. The quality assessment was performed using the Cochrane risk of bias tool, and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to assess the certainty of the evidence. A meta-analysis identified 14 risk factors significantly associated with infant hearing loss. According to the GRADE approach, there were four factors with moderate-certainty evidence (low birth weight(LBW), congenital anomalies, craniofacial anomalies, intracranial hemorrhages), seven factors with low-certainty evidence (ototoxic medications, family history of hearing loss, mechanical ventilation > 5 days, intrauterine infection, admission to neonatal intensive care unit (NICU) > 5 days, mechanical ventilation and asphyxia) and six with extremely-low-certainty evidence (very low birth weight < 1500 g (VLBW), hyperbilirubinemia, sepsis or meningitis, male sex, premature birth, small for gestational age (SGA)). Nevertheless, no significant association was found between infant hearing loss and factors such as small for gestational age (SGA), male sex, and premature birth (P > 0.05).  Conclusion: The identification of these 14 interrelated risk factors can prove advantageous in clinical practice, as these findings could guide hearing screening and parental counseling. Furthermore, prospective research could be conducted to develop risk-based scoring systems based on these factors. What is Known: • Infant hearing loss is a worldwide issue. • Risk factors for this condition are debated. What is New: • This is the first meta-analysis to comprehensively evaluate perinatal and postnatal risk factors for hearing loss in infants. • Intracranial hemorrhage, mechanical ventilation, and low birth weight are associated with infant hearing loss. However, no evidence of an association was found between premature birth, being small for gestational age, or male sex and hearing loss.

Hearing outcomes in preterm infants with confirmed hearing loss

OBJECTIVES

Premature infants are at high risk for hearing loss (HL). The aim of the present study is to assess the frequency of preterm infants affected by HL who experience hearing improvement over months and evaluate possible factors associated with hearing changes.

METHODS

This retrospective study was conducted in a third-level referral audiologic center. Preterm infants with a confirmed diagnosis of sensorineural HL within the first 3 months of life were reassessed at 18 months corrected age using the click-evoked auditory brainstem response between January 1, 2012, and June 30, 2020. The frequency of hearing improvement and associations between possible risk factors and hearing changes were evaluated.

RESULTS

A total of 138 preterm infants (71 male and 67 female; mean gestational age: 30⁺² weeks) were assessed. The percentages of hearing improvement and hearing threshold normalization were 58.7% (81/138) and 35.5% (49/138), respectively. We observed a higher frequency of hearing improvement among preterm infants who had received exclusive breastfeeding or mixed feeding compared with those who had received exclusive infant formula (80% versus 29.3%, P < 0.001).

CONCLUSION

This study confirms the importance of performing a long audiological follow-up and postponing the indication for cochlear implantation in children with a history of preterm birth. Because of the expression of mesenchymal stem cells and high total antioxidant capacity, breast milk might play a protective role in the auditory system of preterm infants. These findings could have important implications for clinical practice, positively impacting the long-term hearing outcomes of preterm infants.

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

IMPORTANCE

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

OBJECTIVE

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

DESIGN, SETTING, AND PARTICIPANTS

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

EXPOSURES

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

MAIN OUTCOMES AND MEASURES

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

RESULTS

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

CONCLUSIONS AND RELEVANCE

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

Assessing Loss to Follow-up After Newborn Hearing Screening in the Neonatal Intensive Care Unit: Sociodemographic Factors That Affect Completion of Initial Audiological Evaluation

OBJECTIVES

Neonatal intensive care unit (NICU) patients are at high risk for congenital hearing loss. Previous studies have found sociodemographic factors associated with loss to follow-up for newborn hearing screening, but none have specifically studied the NICU population. Our objective is to determine if demographics and socioeconomic status is associated with loss to follow-up in a newborn population with extended NICU stay.

DESIGN

A retrospective cohort study was conducted on 443 NICU infants with extended NICU stay utilizing data extracted from infant and maternal medical records at an urban safety-net hospital.

RESULTS

Younger maternal age (adjusted odds ratio [OR] 0.95, confidence interval [CI] 0.91 to 0.99), higher gravidity (adjusted OR 1.39, CI 1.12 to 1.72), and former smoking status (adjusted OR 2.57, CI 1.07-6.18) were identified as independent predictors of loss to follow-up for NHS after conducting a multivariable logistic regression. Demographic and socioeconomic variables, such as sex, parity, birth weight, mode of birth, highest level of maternal education, maternal race/ethnicity, zip code metrics, and maternal language were not found to be associated with loss to follow-up.

CONCLUSIONS

Maternal age, gravidity, and smoking status are risk factors for loss to follow-up for NHS in newborns with extended NICU stay, a group at high risk for hearing loss. Our findings demonstrate that socioeconomic and demographic factors for loss to follow-up in the extended-stay NICU population are distinct from the well-baby population. Further investigation of these patients will allow prioritization of limited resources to subgroups within the extended-stay NICU population at risk for loss to follow-up for newborn hearing screening.

[Childhood hearing screening: achievements, difficulties, and possible ways to improve]

Hearing impairment is the most common sensory impairment that is seen among adults and children. The frequency of congenital hearing loss is well-known due to implementation of newborn hearing screening. Hearing may change throughout a lifetime due to different factors and, therefore, the number of hearing impaired children increases with age. Introduction of universal newborn hearing screening has enabled earlier detection of hearing loss including unilateral and minimal disorders. Nevertheless, despite significant progress made in this field, there is still a group of hearing impairments that stay undiagnosed timely. Auditory neuropathy spectrum disorders, late-onset hearing loss, low-frequency and minimal hearing impairment are sometimes missed in newborn hearing screening or they manifest later. These types of hearing disorders are covered in detail in this review as well as possible ways of increasing the effectiveness of early diagnosis.

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.

Stability of ABR Wave V Threshold in Early Hearing Diagnostics in Children from Selected Groups at Risk of Congenital Hearing Loss

&lt;b&gt;Introduction:&lt;/b&gt; Upon hearing that the "little" patient has trouble with hearing, we are mostly interested in the level of his hearing threshold. When the child is in the first year of life, results can only be achieved by means of ABR test. Subsequent control tests, especially in children from the hearing loss risk groups selected in this study, show that the obtained outcomes are subject to fluctuations. Their fluctuating nature is manifested by the instability of wave V threshold in subsequent diagnostic periods. Such variability often delays the implementation of the appropriate proceeding. Knowledge of the dissimilarity of behavior of the wave V threshold occurring in individual groups at risk of hearing loss allows for the correct interpretation of the obtained results, and thus, effective therapeutic measures. &lt;br&gt;&lt;b&gt;Aim:&lt;/b&gt; The aim of the paper is to analyze the stability of wave V threshold during the first year of life in children from selected risk groups for congenital hearing disorders. &lt;br&gt;&lt;b&gt;Material and methods:&lt;/b&gt; From the patient population of 2,114 individuals examined in 2015-2016 at a reference center participating in the Universal Neonatal Hearing Screening Program in 2015-2016, the results of 250 children were subjected to retrospective analysis. Furthermore, 4 groups of little patients were formed (children with Down syndrome; children with other diseases or damage to the nervous system; children with cleft palate or cleft lip and cleft palate; children with congenital cytomegaly) in whom diagnostic practice revealed variable results of the wave V threshold. We analyzed the results of tests obtained during the first year of the child's life divided into 4 diagnostic periods. &lt;br&gt;&lt;b&gt;Results:&lt;/b&gt; The highest percentage of instability in the established threshold of wave V between individual diagnostic periods occurred in the group of children with cleft palate or cleft lip and cleft palate. In the group of children with Down syndrome, it was observed that the instability of the ABR test results decreased over time. In the group of children with other diseases or damage of the nervous system, the highest percentage of the lack of stable ABR wave V thresholds was observed between the 1st and 2nd as well the 1st and 4th diagnostic periods. On the other hand, in the group of children with congenital CMV, there was a relatively low percentage of instability of results. &lt;br&gt;&lt;b&gt;Conclusions:&lt;/b&gt; (1) Although the ABR test is a diagnostic standard, in particular groups of patients the study is burdened with high variability of measurement results in subsequent diagnostic periods. Such a group of patients are children with cleft palate or cleft lip and cleft palate; therefore, it must receive particular attention in treatment planning; (2) in selected groups at risk of hearing loss, due to the high percentage of children with hearing impairment (70%), the validity of performing newborn hearing screening tests was confirmed.

Exome sequencing in infants with congenital hearing impairment: a population-based cohort study

Congenital hearing impairment (HI) is the most common sensory impairment and can be isolated or part of a syndrome. Diagnosis through newborn hearing screening and management through early intervention, hearing aids and cochlear implantation is well established in the Australian setting; however understanding the genetic basis of congenital HI has been missing. This population-derived cohort comprised infants with moderate-profound bilateral HI born in the 2016-2017 calendar years, detected through newborn hearing screening. Participants were recruited through an integrated paediatric, otolaryngology and genetics HI clinic and offered whole exome sequencing (WES) on a HiSeq4000 or NextSeq500 (Illumina) platform with a targeted average sequencing depth of 100x and chromosome microarray on the Illumina Infinium core exome-24v1.2 platform. Of those approached, 68% (106/156) consented to participate. The rate of genetic diagnosis was 56% (59/106), significantly higher than standard of care (GJB2/6 sequencing only), 21% (22/106). There were clinical implications for the 106 participants: 36% required no further screening, 9% had tailored screening initiated, 2% were offered treatment and 4% had informed care for a complex neurodevelopmental syndrome. WES in this cohort demonstrates the range of diagnoses associated with congenital HI and confirms the genetic heterogeneity of congenital HI. The high diagnostic yield and clinical implications emphasises the need for genomic sequencing to become standard of care.