Risk Factors for Severe and Profound Sensorineural Hearing Loss and Auditory Performance in Children After Cochlear Implant Surgery at Instituto Nacional de Salud del Niño, San Borja, Lima, 2021–2024

Introduction

The World Health Organization estimates that approximately 430 million people worldwide experience some degree of disabling hearing loss requiring rehabilitation.¹ Among the genetically based risk factors are hereditary conditions such as Usher and Waardenburg syndromes, as well as neurofibromatosis type 2. Prenatal factors are also recognized—including infections such as rubella, cytomegalovirus, and toxoplasmosis—along with perinatal conditions such as prematurity and hypoxia, which may cause injury to the auditory nerve, leading to severe or profound hearing loss and negatively impacting language development.^2–5 It is projected that by the year 2050, more than 700 million people will be living with some form of hearing loss, highlighting the growing magnitude of this global health problem.^6,7

In the pediatric population, it is reported that between 1 and 3 per 1,000 newborns present with severe-to-profound sensorineural hearing loss; this number may increase to as many as 8 per 1,000 among neonates who required intensive care, given their increased exposure to risk factors during NICU admission.^8,9 Childhood hearing loss represents a major concern due to its impact on speech and language development, which can result in significant deterioration of cognitive, social, and emotional development if not detected and treated in a timely manner.^10–12

Cochlear implantation has proven to be an effective intervention for restoring auditory function in cases of severe or profound hearing loss, allowing for the progressive development of auditory and verbal skills through auditory rehabilitation.^13–15 However, functional outcomes may vary depending on the presence of associated risk factors, making it essential to evaluate how these conditions influence auditory performance following surgery. Despite the relevance of this topic, no studies have been identified in Peru that examine the relationship between risk factors and auditory performance in pediatric patients undergoing cochlear implantation. In this context, the need arises to address the following question: How do risk factors influence auditory performance after cochlear implantation in children?

The objective of the present study was to determine the association between risk factors and auditory performance among cochlear implant recipients at Instituto Nacional de Salud del Niño, San Borja during the period 2021–2024.

Methods

Results

In the analysis of postoperative cochlear implant patients treated at the National Institute of Child Health–San Borja between 2021 and 2024, PEACH test scores varied according to perinatal characteristics and age at the time of assessment in Table 1. When comparing mode of labor, children born by vaginal labor achieved an average PEACH total score of 68.2 ± 22.1, with performances of 70.5% in the vowel section and 65.8% in the consonant section. In contrast, those born by cesarean section showed slightly lower values, with a mean PEACH total score of 62.4 ± 24.8, 64.1% for vowels, and 60.7% for consonants. Although the mean values were higher in the vaginal labor group, these differences did not reach statistical significance (p = 0.08 for the total score and p = 0.12 for sections A and B) in Table 1.

With respect to age, more marked differences were observed. Children assessed before the age of three demonstrated significantly higher performance, with a PEACH total score of 72.6 ± 19.4, 74.2% for vowels, and 71.0% for consonants. Conversely, those older than three years obtained an average PEACH total score of 58.3 ± 25.7, with 60.1% for vowels and 56.5% for consonants. Comparison between both groups revealed statistically significant differences (p = 0.04), indicating that younger age at assessment is associated with better auditory performance following cochlear implantation in Table 1.

The analysis showed that prematurity was associated with a 3.1-fold higher crude risk (95% CI: 1.4–6.8) compared with term births, and this association persisted in the adjusted model, yielding an OR of 2.8 (95% CI: 1.2–6.5; p = 0.01). Likewise, low birth weight was an important risk factor, with a crude OR of 3.8 (95% CI: 1.7–8.5) and an adjusted OR of 3.5 (95% CI: 1.5–8.1), confirming a statistically significant association (p = 0.003). Severe birth asphyxia was also linked to a greater risk of impaired auditory performance, with a crude OR of 3.6 (95% CI: 1.3–9.8) and an adjusted OR of 3.2 (95% CI: 1.1–9.1; p = 0.03). Similarly, meningitis represented the most impactful factor, with a crude OR of 5.0 (95% CI: 1.4–17.9) and an adjusted OR of 4.7 (95% CI: 1.3–17.0), indicating a markedly increased risk and strong statistical significance (p = 0.02) in Table 2.

Patients from Metropolitan Lima achieved a median score of 80, with an interquartile range (IQR) of 65 to 90, representing the group with the highest outcomes. In contrast, patients from Provincial Lima had a median of 65 [50–75], whereas those from coastal provinces reached a median of 70 [55–85]. Meanwhile, patients from the central region showed a median of 60 [40–75], and those from the southern region recorded the lowest values, with a median of 55 [30–70]. Statistical comparison using the Kruskal–Wallis test yielded a p-value of 0.02, indicating that these differences were statistically significant in Table 3.

The findings showed that a history of exposure to ototoxic medications was present in 26% of children with low PEACH scores, compared with only 8% of those with high scores; this difference was statistically significant (p = 0.007). Likewise, an extended stay in the Intensive Care Unit (>48 hours) had a negative impact on auditory performance: 45% of children with low PEACH scores experienced this condition, whereas it was observed in 22% of those with high scores, representing a significant difference (p = 0.01). Similarly, the requirement for mechanical ventilation for more than five days was also associated with poorer auditory performance; 31% of children with low PEACH scores were exposed to this factor compared with 12% of those with high scores, demonstrating a statistically significant difference (p = 0.02) in Table 4.

In an analysis of 100 postoperative cochlear implant recipients treated at the National Institute of Child Health–San Borja during 2021–2024, the mean age at implantation was 4.2 ± 3.1 years, with no statistically significant difference between the high auditory performance group (PEACH ≥75%) and the low performance group (PEACH <75%)—3.8 ± 2.5 vs. 4.7 ± 3.8 years, respectively (p = 0.15). Regarding sex, 52% of patients were male, with similar distribution across groups (55% in the high PEACH group vs. 48% in the low PEACH group; p = 0.47). Likewise, place of residence was not associated with performance: 45% resided in Metropolitan Lima (50% among high PEACH vs. 38% among low PEACH; p = 0.22) in Table 5.

Analysis of perinatal conditions and clinical history identified significant associations. Prematurity (<37 weeks) was present in 38% of the sample and was more frequent in the low PEACH group (57%) than in the high PEACH group (24%), a statistically significant difference (p = 0.001). Similarly, low birth weight was recorded in 32% of patients and was more common among those with low PEACH (48%) compared with those with high PEACH (19%; p = 0.003). Severe perinatal asphyxia was reported in 18% overall, with a predominance in the low PEACH group (29% vs. 10%; p = 0.02). Finally, meningitis was a antecedent in 12% of children and was more prevalent among those with low PEACH (21%) than among those with high PEACH (5%; p = 0.01) in Table 5.

The results show that prematurity (<37 weeks) was present in 63.2% of cases with low auditory performance, and was associated with a significantly increased crude risk (PR: 2.8; 95% CI: 1.6–4.9; p < 0.001). In multivariate analysis this factor remained an independent predictor, with an adjusted risk of 2.5 (95% CI: 1.4–4.4) in the logistic model and 2.6 (95% CI: 1.5–4.5) in the Poisson model with robust variance in Table 6.

Similarly, low birth weight was associated with poorer performance in 62.5% of patients, yielding a crude risk of 2.6 (95% CI: 1.5–4.5; p = 0.001). This association remained significant after adjustment in both the logistic model (aPR: 2.3; 95% CI: 1.3–4.1) and the Poisson model (aPR: 2.4; 95% CI: 1.4–4.2) in Table 6.

Severe perinatal asphyxia was observed in 61.1% of patients with low PEACH scores, with a crude risk of 2.4 (95% CI: 1.2–4.8; p = 0.01). In adjusted analysis this factor showed borderline significance (aPR: 2.1; 95% CI: 1.0–4.3 in the logistic model; aPR: 2.2; 95% CI: 1.1–4.5 in the Poisson model) in Table 6.

Meningitis had the largest impact: 75.0% of affected patients had low auditory performance, with a crude risk of 3.5 (95% CI: 1.6–7.6; p = 0.002) and a similarly significant adjusted risk in both models (logistic: aPR: 3.1; 95% CI: 1.4–6.9; Poisson: aPR: 3.2; 95% CI: 1.5–7.0) in Table 6.

Finally, age greater than 3 years at implantation was associated in the bivariate analysis (PR: 1.8; 95% CI: 1.1–3.0; p = 0.02), but lost statistical significance in multivariate analysis, remaining only as a trend toward higher risk (logistic: aPR: 1.6; 95% CI: 0.9–2.8; Poisson: aPR: 1.7; 95% CI: 1.0–2.9) in Table 6.

Discussion

In this cohort of 100 postoperative cochlear implant recipients treated at the National Institute of Child Health–San Borja between 2021 and 2024, auditory performance as measured by the PEACH scale was significantly influenced by perinatal and early developmental factors. These findings are consistent with those reported by Díaz et al.,²⁰ who highlighted the relevance of early-life complications on long-term auditory outcomes.

Prematurity and low birth weight were among the strongest predictors of reduced auditory performance. In the present study, 63.2% of premature children and 62.5% of those with low birth weight showed low PEACH scores, with adjusted prevalence ratios ranging from 2.3 to 2.6 across multivariate models. This suggests that preterm birth and intrauterine growth restriction can compromise auditory processing pathways through mechanisms such as delayed neurosensory maturation, chronic hypoxia, and myelination deficits—processes that are critical for effective auditory encoding and cortical integration. Similar findings were described by Boboshko, Savenko et al., and Aldè et al.,^21–23 who proposed that neonatal hypoxic–ischemic injury and immature neural synchronization contribute to the vulnerability of the auditory cortex in preterm infants.

Age at implantation also played a decisive role in auditory outcomes. Children implanted before the age of three demonstrated significantly higher PEACH scores (72.6 ± 19.4) compared with those implanted later (58.3 ± 25.7; p = 0.04). This agrees with the observations of Wahyu et al. and Culbertson et al.,^24,25 who emphasized that earlier auditory stimulation through cochlear implantation promotes optimal neural plasticity and language acquisition. During the first three years of life, synaptic density and cortical mapping remain highly adaptable; therefore, earlier activation of the auditory pathway enhances the establishment of functional auditory–linguistic networks.

Among the clinical conditions analyzed, meningitis emerged as the most detrimental factor, with affected patients exhibiting a threefold higher adjusted risk of poor auditory performance (aPR = 3.1–3.2, p < 0.01). The pathophysiological mechanisms underlying this association are well recognized—post-meningitic cochlear ossification, spiral ganglion neuron loss, and central auditory sequelae can all limit the effectiveness of electrical stimulation.²⁶ Our results parallel those reported by Singhal et al.,²⁶ who demonstrated significantly lower speech perception and auditory comprehension among post-meningitic implant recipients. These findings underscore the importance of rapid surgical intervention following meningitis to prevent cochlear fibrosis and optimize postoperative outcomes.²⁷

In addition, exposure to ototoxic agents and prolonged mechanical ventilation were significantly associated with lower PEACH scores (p < 0.01). Children with a history of ototoxic drug use had a threefold higher prevalence of poor auditory performance (26% vs. 8%), while prolonged ICU stay (>48 h) and mechanical ventilation (>5 days) were also linked to reduced auditory outcomes (45% and 31%, respectively, in the low PEACH group). These findings are consistent with the evidence presented by Naik et al. and other authors,^20,28,29 who recommend systematic audiologic monitoring for patients exposed to aminoglycosides, loop diuretics, or prolonged hypoxic conditions during intensive care, given their potential to cause irreversible cochlear or neural damage.

Overall, the present findings indicate that auditory performance following cochlear implantation is determined not only by surgical and technological variables but also by early perinatal risk factors that influence auditory plasticity. Early diagnosis, timely intervention, and continuous auditory rehabilitation are therefore critical to maximizing post-implant outcomes. In line with Naik et al.,²⁹ comprehensive management should include structured family counseling and long-term audiologic follow-up to strengthen auditory–linguistic development and social integration in affected children.

Conclusion

In this study, a significant association was found between several risk factors and poorer auditory performance in hearing-impaired children who underwent cochlear implantation. The most strongly associated factors were prematurity, low birth weight, severe perinatal asphyxia, and hydrocephalus, all of which were linked to less favorable auditory and language development outcomes following surgery.