Age and Other Factors Affecting the Outcome of AABR Screening in Neonates

Referral rate and false-positive rates in a hearing screening program among high-risk newborns

AIM

More studies exploring referral rates and false-positive rates are needed to make hearing screening programs in newborns better and cost-effective. Our aim was to study the referral and false-positivity rates among high-risk newborns in our hearing screening program and to analyze the factors potentially associated with false-positive hearing screening test results.

METHODS

A retrospective cohort study was done among the newborns hospitalized at a university hospital from January 2009 to December 2014 that underwent hearing screening with a two-staged AABR screening protocol. Referral rates and false-positivity rates were calculated and possible risk factors for false-positivity were analyzed.

RESULTS

4512 newborns were screened for hearing loss in the neonatology department. The referral rate for the two-staged AABR-only screening was 3.8% with false-positivity being 2.9%. Our study showed that the higher the birthweight or gestational age of the newborn, the lower the odds of the hearing screening results being false-positive, and the higher the chronological age of the infant at the time of screening, the higher the odds of the results being false-positive. Our study did not show a clear association between the mode of delivery or gender and false-positivity.

CONCLUSION

Among high-risk infants, prematurity and low-birthweight increased the rate of false-positivity in the hearing screening, and the chronological age at the time of the test seems to be significantly associated with false-positivity.

Retinol and Pro-Vitamin A Carotenoid Nutritional Status during Pregnancy Is Associated with Newborn Hearing Screen Results

The prenatal period is critical for auditory development; thus, prenatal influences on auditory development may significantly impact long-term hearing ability. While previous studies identified a protective effect of carotenoids on adult hearing, the impact of these nutrients on hearing outcomes in neonates is not well understood. The purpose of this study is to investigate the relationship between maternal and umbilical cord plasma retinol and carotenoid concentrations and abnormal newborn hearing screen (NHS) results. Mother-infant dyads (n = 546) were enrolled at delivery. Plasma samples were analyzed using HPLC and LC-MS/MS. NHS results were obtained from medical records. Statistical analysis utilized Mann-Whitney U tests and logistic regression models, with p ≤ 0.05 considered statistically significant. Abnormal NHS results were observed in 8.5% of infants. Higher median cord retinol (187.4 vs. 162.2 μg/L, p = 0.01), maternal trans-β-carotene (206.1 vs. 149.4 μg/L, p = 0.02), maternal cis-β-carotene (15.9 vs. 11.2 μg/L, p = 0.02), and cord trans-β-carotene (15.5 vs. 8.0 μg/L, p = 0.04) were associated with abnormal NHS. Significant associations between natural log-transformed retinol and β-carotene concentrations and abnormal NHS results remained after adjustment for smoking status, maternal age, and corrected gestational age. Further studies should investigate if congenital metabolic deficiencies, pesticide contamination of carotenoid-rich foods, maternal hypothyroidism, or other variables mediate this relationship.

Effect of delivery mode on neonate auditory brainstem responses to air- and bone-conducted stimuli

OBJECTIVES

The object of this study was to examine if caesarean section delivered neonates have different middle ear function relative to neonates with vaginal delivery.

METHODS

Auditory brainstem responses (ABRs) were examined in caesarean section delivered (n = 23) and vaginally delivered (n = 29) neonates. ABRs were also evoked with air- and bone-conducted stimuli (i.e., clicks and CE-Chirps) and presented at a screening intensity level (i.e., 30 dB nHL). Wave V latencies and amplitudes were examined as a function of mode of delivery and stimuli.

RESULTS

Statistically significant longer wave V latencies evoked with air-conducted stimuli were seen in caesarean section delivered neonates (p = .042). There was no statistically significant difference in wave V latencies with bone-conducted stimuli among the two groups of neonates (p = .42). There were no significant differences in wave V amplitude between neonates with caesarean section and vaginal delivery for air-conducted (p = .42) stimuli. Wave V amplitudes were not significantly different as a function of mode of delivery with CE-Chirp stimulus (p = .41). Wave V amplitudes were significantly larger for the caesarean section delivered neonates with the bone-conducted click stimulus (p = .036).

CONCLUSIONS

The ABR wave V latency disparity with air- and bone-conducted stimuli support the notion that differences in middle ear function exist between the two groups of newborns. It was speculated that delayed fluid resorption in the middle ear exists in neonates with caesarean section delivery compared to those with vaginal delivery.

[Duration of automated auditory brainstem response test for the initial hearing screening and influencing factors for the duration in neonates]

OBJECTIVE

To study the duration of automated auditory brainstem response (AABR) test for initial hearing screening and the factors influencing the duration in neonates.

METHODS

A total of 472 neonates who were admitted to the neonatal intensive care unit (NICU) were enrolled as the study group and 182 healthy neonates were enrolled as the healthy control group. The influence of the duration of AABR test on the initial screening results was observed in the two groups. The influencing factors for the AABR test duration were analyzed.

RESULTS

In the AABR screening of 180, 360, and 540 seconds, the study group had a failure rate of 41.5%, 28.4%, and 24.4% respectively, while the healthy control group had a failure rate of 31.3%, 19.8%, and 15.4% respectively, showing a decreasing trend with the extension of test time in both groups (P<0.05). In the two groups, the screening results of 180-second testing were moderately consistent with those of 360- or 540-second testing (Kappa<0.75, P<0.05), and the screening results of 360-second testing were highly consistent with those of 540-second testing (Kappa>0.75, P<0.05). In the study group, the median duration of AABR test was 108 seconds (95%CI: 97-120 seconds), which was significantly longer than the duration of 75 seconds (95%CI: 65-85 seconds) in the healthy control group (P<0.05). The Cox regression analysis showed that maternal age ≥35 years, anemia, and electrolyte disturbance (RR<1, P<0.05) were independent risk factors for prolonged AABR test duration, while the prolonged continuous positive airway pressure-assisted ventilation was a protective factor (RR>1, P<0.05).

CONCLUSIONS

The AABR test time of 360-540 seconds for initial hearing screening helps to reduce false positive results due to environmental and risk factors in neonates. It may be useful to reduce the false positive results of AABR screening before discharge by taking corresponding intervention measures for NICU neonates with high risk factors.

Characteristics of the Frequency-Following Response to Speech in Neonates and Potential Applicability in Clinical Practice: A Systematic Review

Purpose We sought to critically analyze and evaluate published evidence regarding feasibility and clinical potential for predicting neurodevelopmental outcomes of the frequency-following responses (FFRs) to speech recordings in neonates (birth to 28 days). Method A systematic search of MeSH terms in the Cumulative Index to Nursing and Allied HealthLiterature, Embase, Google Scholar, Ovid Medline (R) and E-Pub Ahead of Print, In-Process & Other Non-Indexed Citations and Daily, Web of Science, SCOPUS, COCHRANE Library, and ClinicalTrials.gov was performed. Manual review of all items identified in the search was performed by two independent reviewers. Articles were evaluated based on the level of methodological quality and evidence according to the RTI item bank. Results Seven articles met inclusion criteria. None of the included studies reported neurodevelopmental outcomes past 3 months of age. Quality of the evidence ranged from moderate to high. Protocol variations were frequent. Conclusions Based on this systematic review, the FFR to speech can capture both temporal and spectral acoustic features in neonates. It can accurately be recorded in a fast and easy manner at the infant's bedside. However, at this time, further studies are needed to identify and validate which FFR features could be incorporated as an addition to standard evaluation of infant sound processing evaluation in subcortico-cortical networks. This review identifies the need for further research focused on identifying specific features of the neonatal FFRs, those with predictive value for early childhood outcomes to help guide targeted early speech and hearing interventions.