The most severe cases of hearing loss can happen at any age, but they usually start before or right after birth. Given that speech and language are generally acquired through the auditory system, speech and hearing are connected, i.e., a problem with one could indicate a problem with the other [1].

Speech and intellectual development function impairments can result from these effects. With an incidence of irreversible hearing loss ranging from 2 to 3/1000 of live births, congenital hearing loss has recently been identified as one of the most prevalent birth defects found in neonates. But now that the National Program for the Prevention and Control of Deafness (NPPCD) has been established, there is a resurgence of interest in this enormous public health issue [2].

In most countries, newborn hearing screening programmes that screen only high-risk infants have been in existence for more than 20 years. However, this group of infants with hearing loss comprises only 50% of newborn population with hearing loss. Therefore, hearing screening programs that screened only high-risk neonates missed out 50% of hearing –impaired newborns, who are from among infants without any risks factors. Also, as hearing loss is an invisible disability it cannot be passively identified until the child fails to develop speech and language. It has been estimated that untreated deaf infants can cost society approximately $1,126,300 over the course of their lifetime. Therefore, early detection is a vitally important element in providing appropriate support for deaf and hearing-impaired babies that will help them enjoy equal opportunities in society alongside all other children [3].

Hearing impairment in infants should be identified as early as possible to enable interventions to take full advantage of the plasticity of developing sensory system. Hearing integrity in the first 3-4 years of life, the critical period, is essential for acquisition of speech and language. Unfortunately, by the time hearing loss in infancy and early childhood is suspected, audiologically evaluated and appropriately managed two or more of these critical years have elapsed and the child has lost an enormous developmental advantage. The onus lies on modern physicians to innovate culturally acceptable ways of implementing Infant Hearing Screening programs [3].

The cost-effectiveness of a screening intervention was largely dependent upon two key factors. As would be expected, the cost (per patient) of the intervention drives the model substantially, with higher costs leading to higher cost-effectiveness ratios. Likewise, the baseline prevalence (risk) of hearing impairment also affected the results. In scenarios where the baseline risk was low, the intervention was less likely to be cost-effective compared to when the baseline risk was high.

Aim and Objectives

To evaluate the duration of admission and birth weight and their association with presence of Hearing Loss in BERA among High Risk Infants admitted to NICU

Study Setting 

The present study was carried out in a tertiary care teaching hospital at DRPGMC, Kangra at Tanda, Himachal Pradesh.

Study Population 

50 infants of either sex, fulfilling the inclusion criteria admitted in the Department of Paediatrics, DRPGMC comprised the study population.

Study Design 

The study was conducted as a Cross sectional prospective study.

Study Sample 

50 infants who visited the hospital during study period who fulfilled eligibility criteria comprised the study sample.

Sample Size Estimation

50 infants fulfilling the inclusion and exclusion criteria during the study period were included in the study.

Sampling Technique 

Universal sampling

Study Period

The study was conducted during the period starting from Jun 2020 to Dec 2021. Data collection period was from June 2020 to May 2021.

Inclusion Criteria

• 50 patients of age 1 years and below of either sex 

• 50  patients of Hyperbilirubinemia (total bilirubin>20mg/dl), Meningitis, Sepsis, NICU admission (stay more than 5 days)

Exclusion Criteria

• Infants with congenital anomalies of external ear

• Family history of hearing loss

Study Tools 

BERA (Neurosoft, Neuro Audio, Russia, 2019).

Methodology 

50 Infants fulfilling all the inclusion criteria were enrolled in the study at the time of their discharge from the Department of Paediatrics, DRPGMC Tanda for the duration of one year. The infants underwent behavioural audiometry at the time of enrolment whereas BERA was conducted twice; once at the time of discharge from hospital and then after a period of three months. The infants showing hearing loss were treated as per department protocol and standard medical literature.

Procedure Followed 

Each infant fulfilling the inclusion and exclusion criteria during the study period was recruited after the due consent of the parents. The parents were sensitised regarding the Universal Newborn Screening and the need for the evaluation of the hearing in the high risk infants. They were also counselled regarding the free will of participation in the study as study participants and the financial disclosure during the study was also done. Following the filling of Informed Consent and Information Sheet the examination was done by the Principal Investigator and the case record and case Performa were filled. Examination included detailed history of the patient, local and systemic examination. The Audiologist and Speech Therapist (Dept. ENT, DRPGMC) performed the behavioural audiometry. The infants were then sedated using the syrup promethazine (0.5mg/kg dose, single dose) The 

Table 1: Auditory Brainstem Response (ABR) Test Parameters

BERA was conducted by placing the infant in supine position. The electrodes positioned as per the Dual Channel System Configuration (1 at the vertex and 2 at the mastoid). The electrode impedance and the circuit electrical noise was checked thereafter the sound stimulus was given using the following system settings.

The intensity was lower from 90 dB Hl to 30 dB HL to identify the lowest threshold at which the wave V can be elicited. The multiple recordings were taken for both the ears and superimposed to check the reproducibility of wave V. The infant was then kept in recovery room under observation till the complete reversal of the sedation and thereafter handed over to the parents.

Statistical Analysis

Data entry was done in MS Excel 2016 and data analysis was carried out using SPSS version 22.0. Means and proportions were calculated for continuous and categorical variables respectively. Difference in means were tested using chi square test, for statistical significance in differences. A p-value<0.05 was considered statistically significant.

Ethical Considerations

Informed written consent was obtained from all parent/ guardian of the infant before including them in the study. Institute Ethical Committee approval along was obtained before the study was started. The University Ethics Committee approval was also obtained before the study was started.

Maximum of the study participants were in the age group of 1-3 months (34%). The mean age of the study participants was observed to be 5.8±2.9 months. Majority of the study participants were females (64%), while 36% of them were males.

Meningitis was the most common indication for NICU admission (42%) followed by Neonatal jaundice (24%).

Majority of the study infants were admitted to the NICU for a duration of 10-20 days (60.0%).

No significant association was observed between duration of NICU admission and presence of hearing loss (p-value-0.543)

Table 2: Age and Gender Distribution of Study Participants (n = 50)

Table 3: Distribution of Study Participants Based on BERA Inference (n = 50)

Profound hearing loss and minimal hearing loss was observed in 14% and 6% of the infants respectively

LBW and VLBW was present in 6% and 2% of the study participants, respectively.

Higher proportion of infants with LBW had hearing loss as compared to those with normal birth weight. However, this difference was not statistically significant (p-value–0.072) 

The present study was carried out with an aim to evaluate the duration of admission and birth weight and their association with presence of Hearing Loss in BERA among High Risk Infants admitted to NICU at a tertiary care teaching hospital in Kangra at Tanda, North India. 

Maximum of the study participants were in the age group of 1-3 months (34%) and majority were females (64%). Majority of the study infants were admitted to the NICU for a duration of 10-20 days (60.0%). LBW and VLBW was present in 6% and 2% of the study participants, respectively. Profound hearing loss and minimal hearing loss was observed in 14% and 6% of the infants respectively. No significant association was observed between duration of NICU admission, birth weight and hearing loss.

In the study by Thakkar D. et al. [4] they have voiced that the most common risk factor among children with hearing loss was consanguineous marriage (24%) followed by neonatal jaundice (16%), low birth weight (12%) and others. The most common risk factor in patients under<1-year age group with decreased hearing was low birth weight (33.33%). Warasanti E.S. et al. [5] study results stated that most risk factor was LBW of 15 infants (78.95%). In thier study also, no statistically significant association was seen between the risk factor i.e. LBW. 

Table 4: Distribution of Study Participants Based on Indication for NICU Admission (n = 50)

Majority of the study infants were admitted to the NICU for a duration of 10-20 days (60.0%).

Table 5: Distribution of Study Participants Based on Duration of NICU Admission (n = 50)

No significant association was observed between duration of NICU admission and presence of hearing loss (p-value-0.543)

Table 6: Association between Duration of NICU Admission and Presence of Hearing Loss in BERA (n = 50)

* Chi Square test was applied to test statistical difference in proportions

The importance of developing protocols for detecting postnatal hearing loss must not be understated. Although targeted surveillance has traditionally been recommended to detect postnatal hearing loss, there is significant debate surrounding this method. After diagnosis, the infant or toddler is given interdisciplinary care in an interdisciplinary team of phoniatrist and paediatric audiologist, ENT specialist, paediatric acoustician, paediatrician, neuro-paediatrician, paediatric cardiologist, human geneticist, ophthalmologist, possibly paediatric psychologist and the local paediatrician and ENT specialist. A high level of competency and professionalism is required in the care of infants and toddlers with hearing impairments.

The study concluded that higher proportions of infants with LBW and NICU admission for aduration of 21-30 days were found to have hearing loss but this difference was not found to be statistically significant.

1. Živić D. and Lj Ž. "Comparative analysis of reaction to sound stimulation of premature and full term babies during the first days after birth." 4th European Congress of Otorhinolaryngology Head and Neck Surgery, vol. 13, no. 18, 2000, pp. 247-255.

2. Moeller M.P. et al. "Vocalizations of infants with hearing loss compared with infants with normal hearing: Part II–transition to words." Ear and Hearing, vol. 28, no. 5, 2007, pp. 628-642.

3. Burke M.J.  et al. "The economics of screening infants at risk of hearing impairment: An international analysis." International Journal of Pediatric Otorhinolaryngology, vol. 76, no. 2, 2012, pp. 212-218.

4. Thakkar D. and Barot D. "Brainstem-evoked response audiometry in pediatric age group." Indian Journal of Otology, vol. 24, no. 4, 2018, p. 246.

5. Warasanti E.S. et al. "Comparison results of automated auditory brainstem response and brainstem evoked response audiometry for hearing loss detection in high-risk infants." Open Access Macedonian Journal of Medical Sciences, vol. 8, no. B, 2020, pp. 593-596.