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 Introduction: Studies 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. Objective: To verify the incidence of hearing loss in neonates who have no other associated risk indicators, born to mothers treated for malaria during pregnancy. Methods: A 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. Results: All 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. Conclusion: The present study did not identify any cases of hearing loss in neonates born to mothers who used antimalarial drugs during gestation.

背景：已有研究证实抗疟药物对用药个体具有耳毒性，但对于妊娠期服用此类药物的母亲所诞新生儿的听觉系统受此类药物毒性影响的情况，目前仍知之甚少。
研究目的：验证妊娠期因疟疾接受治疗的母亲所产下无其他相关高危因素的新生儿，其听力损失的发生率。
研究方法：本研究为回顾性定量队列研究，在位于巴西朗多尼亚州波多韦柳市的阿里·皮涅罗博士基础医院（Hospital de Base Dr. Ary Pinheiro）与利米尔诊所（Clínica Limiar）开展。研究样本共纳入527名新生儿，分为两组：妊娠期暴露于抗疟药物组（n=32）与非暴露组（n=495）。数据收集于2014年9月至2015年12月期间完成，通过对新生儿母亲及/或监护人进行访谈、查阅新生儿与母亲的医疗记录，以及上述两家机构的新生儿听力筛查数据库获取相关数据。
研究结果：暴露组的所有新生儿均通过首次新生儿听力筛查，筛查方式为瞬态诱发性耳声发射（transient evoked otoacoustic emissions）结合自动听性脑干反应（automated brainstem auditory evoked potential）检测。非暴露组共有30名新生儿首次筛查未通过并接受复筛，其中1名复筛仍未通过并被转诊至诊断环节，经诊断其听力结果处于正常范围。暴露组新生儿最常见的疟原虫感染类型为间日疟原虫（Plasmodium vivax），该感染在妊娠各孕期的分布较为均衡；最常用的抗疟治疗药物为氯喹，且多在妊娠晚期给药；上述结果均未对研究新生儿的听力学检测结果产生显著影响。
研究结论：本研究未在妊娠期服用抗疟药物的母亲所产下的新生儿中发现任何听力损失病例。