Assessment of the Peripheral and Central Auditory System in Infants Whose Mothers Tested Positive for COVID-19 During...

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), a new member of the coronavirus family. While respiratory transmission is the main route, concerns have arisen regarding possible vertical transmission, which refers to the transmission of the virus from mother to fetus through the dissemination of viral particles in the amniotic fluid. Fetal viral infection via the placenta can affect the formation of the auditory system and lead to congenital hearing disorders. The aim of this research was to investigate the effects of vertical exposure to COVID-19 on the auditory system of newborns.

The study included a study group (SG) and a control group (CG). Selected during neonatal hearing screening, the SG consisted of 23 infants up to 1 year old whose mothers had been infected with SARS-CoV-2. The CG consisted of 15 infants whose mothers became pregnant after the end of the pandemic, had tested negative for COVID-19, and had no respiratory symptoms during pregnancy. The assessments for both groups were brainstem auditory evoked potentials (BAEPs), tympanometry, transient evoked otoacoustic emissions (TEOAEs), and distortion product otoacoustic emissions (DPOAEs). The research was divided into two studies, one cross-sectional and the other longitudinal.

All participants exhibited absolute latencies within the normal range for waves I, III, and V, although in the SG, there was a statistically significant increase in the latency of wave I in the left ear. In terms of OAEs, in the SG, there appeared to be a tendency for TEOAEs to be absent at high frequencies. Over several months, there was a general decrease in the amplitude of high-frequency responses in both TEOAEs and DPOAEs.

No evidence was found that vertical exposure to COVID-19 causes hearing loss, although there were signs of possible deterioration in hair cell functioning.