Auditory evaluation of infants born to COVID19 positive mothers

COVID-19 infection can cause a wide spectrum of symptoms. The audio-vestibular system can also be involved, but there is still debate about this so findings need to be considered carefully. Furthermore, mother to fetus intrauterine transmission of COVID-19 infection in pregnant women is controversial. Few studies are available about the audio-vestibular symptomatology of newborns with intrauterine COVID19 exposure.

Objectives: This study investigates the possible correlation between the COVID19 gestational infection and hearing impairment onset in newborns. The involvement of hearing in COVID19 is verified so the timing and methodology of audiological evaluation of children can be planned.

Methods: Children were subject to newborn hearing screening and audiological evaluation. Newborn hearing screening is carried out prior to hospital discharge using the Automatic Transient Evoked Otoacoustic Emissions test. Audiological evaluation is performed within the child age of 4 months by using maternal, pregnancy, and perinatal case history, COVID19 case history, otoscopy, acoustic immittance test, Distortion Product Otoacoustic Emissions test, and the Auditory Brainstem Response test.

Results: 63 children were included in the study. 82.5% of these children were subjects of the newborn hearing screening program. The remaining 11 newborns were not subjected to hearing screening due to isolation measures and their audiological evaluation was carried out directly. Only one of 52 screened neonates showed a bilateral REFER test result but hearing threshold was normal at audiological evaluation. Audiological evaluation showed normal bilateral ABR thresholds in 59/63 children. Four children (6.3% of the total) had ABR threshold alterations but two showed normal threshold at ABR retest performed within 1 month of the first. The other two infants showed monolateral ABR alterations but one of these had a concomitant middle ear effusion. In conclusion, only one child (1.6% of the sample) had an altered ABR. This child had shown one positive SARS-CoV-2 swab in the absence of risk factors for hearing loss.

Conclusion: This study finds no evidence that maternal COVID19 infection is a risk factor in the development of congenital hearing loss in newborns.