Impact of Gestational Age on Neonatal Hearing Screening in Vaginally-Born Late-Preterm and Early-Term Infants

Abstract

Background: Late-preterm and early-term (LP-ET) infants, defined herein as 35⁰-37⁶ weeks' gestation, often fail on 1st otoacoustic emissions (OAE) test. Hypothesis: LP-ET infants fail more than term infants (38⁰-42 weeks' gestation) on the 1st OAE test. Aim: To evaluate the effect of gestational age on the 1st OAE test. Methods: We studied 1,572 vaginally-delivered (VD) infants ≥35 weeks' gestation (1.1.2011-30.9.2011). Perinatal and neonatal variables and results of OAE tests were recorded. Results: LP-ET infants, compared to full-term infants, had a significantly 2-fold higher need for repeated hearing tests: 80.2 versus 43.3 tests/1,000 neonates, respectively (p = 0.026). Univariate analysis showed that late prematurity and age at 1st OAE were significantly associated with failure on 1st OAE. At age 24-42 h, failure on 1st OAE was 2-fold higher in the LP-ET infants than in full-term infants: 9.4 versus 4.7% (p = 0.02). Risk for failure on 1st OAE was age-dependent: 9-fold higher when 1st OAE was performed at 24-42 h of age (5.3%) versus 0.6% after age 42 h. Multivariate analysis showed that variables that were independently significantly associated with failure on 1st OAE included late prematurity (OR 2.0 (1.1-3.7)) and age at 1st OAE (OR 9.2 (1.2-70.7)). Conclusions: Compared to term infants, VD LP-ET infants had 2-fold higher rates of failure on 1st OAE (up to 42 h of life) and needed repeated hearing tests. Failure rates after 42 h become negligible in both groups. In VD LP-ET infants, 1st OAE is better performed after 42 h of age.

Efeitos da prematuridade na aquisição da linguagem e na maturação auditiva: revisão sistemática

“…In a study that evaluated the effect of gestational age in the baby hearing test carried out with Otoacoustic Emissions (OAE), the authors (36) compared late preterm infants to full-term infants and found it was two times more necessary to repeat listening tests in the first group, because these children presented higher failure rates in the first EOA performed up to 42 hours after birth. As there was no significance in failure rates after 42 hours in both groups, they concluded that the results in late preterm infants are related to late maturation of the auditory system after birth, in agreement with one of the studies selected (34) , in which it was verified that maturation of the auditory system has a greater influence than factors such as weight at birth.…”

“…Considering hearing conditions, it is known that auditory monitoring of premature children is also extremely important, not only to avoid or remedy hearing problems, but also to minimize their effects on language acquisition. Some research results suggest that prematurity affects the maturation process of the central auditory nervous system, including maturation of the auditory pathway, as well as the weight at birth factor, which may negatively impact the process of language acquisition and learning (33)(34)(35)(36) . In line with these works, another study (47) observed a statistically significant association among maturation of the auditory pathway, cognition and communication (at 12 months) and receptive language (at 24 months).…”

“…In these, assessments of language and hearing were part of the procedures to carry out such studies in a complementary basis (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27) . On the other hand, other studies found focused mainly on language and/or hearing impairments in premature infants (28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38) .…”

Change to Hearing Loss–Related Risks and Screening in Preterm Infants

“…57 Late-preterm and early-term (35–37 6 weeks' gestation) infants born vaginally have twice the OAE failure rate within 42 hours after birth compared with term infants, and it is therefore recommended that the first OAE test be performed 42 hours after birth. 58 The OAEs of the tested ear can be suppressed by acoustic stimulation of the contralateral ear, and this efferent system is not activated at low noise levels. OAE tests are usually performed in hospitals or clinics, with ambient noise levels as high as 60 to 70 dB sound pressure levels (SPL), and thus the OAEs in the tested ear may be affected by noise stimulation in the contralateral ear.…”

“…91 For preterm infants with transvaginal delivery, the first OAE screening is recommended 42 hours after birth. 58 For preterm infants with a gestational age of <28 weeks, the developmental maturation of hearing potential appears prior to the corrected gestational age of 80 weeks. Hearing levels in preterm infants may improve over time, so before cochlear implantation, the delayed auditory maturation and initial hearing level of infants should take into account.…”