Abstract
This study of tobacco exposure and auditory processes was conducted in a predominantly low-income population of 40 pregnant women and their newborns. Urinary cotinine concentrations and self-reported smoking status were obtained from the mother during the first prenatal care visit. Auditory brainstem-evoked responses (ABRs) were recorded in neonates to assess neuroelectrical activity of the auditory nerve following a sound stimulus. Infants of mothers with the highest cotinine concentrations (> 1,000 ng/ml) responded at a rate that was four times greater (hazard ratio 4.1, 95% confidence interval 1.4–11.5) than infants of non-smoking mothers (cotinine ≤ 15 ng/ml). Associations with more moderate cotinine concentrations (> 15–1,000 ng/ml) were not observed. Enhanced ABRs may disrupt auditory processes related to speech perception, negatively affecting reading and language development during childhood. The results suggest that tobacco exposure during pregnancy may impair auditory function.
Acknowledgements
The authors thank Linda Cowan, PhD for epidemiologic support and contribution to study design and implementation and Kiera Stephens, AuD for assistance with data collection. This study was supported by OHRS Award # HR06-170 from the Oklahoma Center for the Advancement of Science and Technology and from Grant # 5 T42 OH008421-03 from the National Institute for Occupational Safety and Health through the Southwest Center for Occupational and Environmental Health.
Disclosure of interest: The authors declare no conflicts of interest.