Hearing of neonates without risk indicators for hearing loss and use of antimalarial drugs during pregnancy: a historical cohort study in the Northern Region of Brazil

Abstract

IntroductionStudies have demonstrated the ototoxic effects of antimalarial drugs in individuals who receive these drugs, but little is known regarding the toxicity of these drugs in the newborn auditory system when administered to the mother receive the drug during pregnancy. ObjectiveTo verify the incidence of hearing loss in neonates who have no other associated risk indicators, born to mothers treated for malaria during pregnancy. MethodsA retrospective, quantitative cohort study was developed at Hospital de Base Dr. Ary Pinheiro and Clínica Limiar, both located in the municipality of Porto Velho (Rondônia). The sample consisted of 527 newborns divided into two groups: exposed to antimalarials drugs during pregnancy group (n = 32) and non-exposed group (n = 495). Data collection took place from September 2014 to December 2015, through an interview with the mothers and/or guardians of the newborn, through the newborns’ and the mothers’ records, and the neonatal hearing screening database of the above-mentioned institutions. ResultsAll the neonates in the exposed group, assessed through the recording of transient otoacoustic emissions associated with the automated brainstem auditory evoked potential test, underwent neonatal hearing screening in the first examination. Among the newborns in the non-exposed group, 30 showed failure and were retested. Of these, one continued to fail and was referred for diagnosis, in whom the results showed to be within the normal range. Among the neonates of the exposed group, infection with Plasmodium vivax was the most frequent, and was similarly distributed among the gestational trimesters, and chloroquine was the most commonly used antimalarial drug treatment more often given during the third trimester; these findings did not show any influence on the audiological findings of the studied neonates. ConclusionThe present study did not identify any cases of hearing loss in neonates born to mothers who used antimalarial drugs during gestation.