title: Maternal prenatal smoking and hearing loss among adolescents.
abstract: OBJECTIVE
  Although smoking and secondhand smoke exposure are associated with sensorineural hearing loss (SNHL) in children and adults, the possible association between prenatal smoke exposure and hearing loss has not been investigated despite the fact that more than 12% of US children experience such prenatal exposure each year.
  
  
  OBJECTIVE
  To investigate whether exposure to prenatal tobacco smoke is independently associated with SNHL in adolescents.
  
  
  METHODS
  Cross-sectional data were examined for 964 adolescents aged 12 to 15 years from the National Health and Nutrition Examination Survey 2005-2006.
  
  
  METHODS
  Participants underwent standardized audiometric testing, and serum cotinine levels and self-reports were used to identify adolescents exposed to secondhand smoke or active smokers.
  
  
  METHODS
  Prenatal exposure was defined as an affirmative parental response to, "Did [Sample Person's Name] biological mother smoke at any time while she was pregnant with [him/her]?" Sensorineural hearing loss was defined as an average pure-tone hearing level more than 15 dB for 0.5, 1, and 2 kHz (low frequency) and 3, 4, 6, and 8 kHz (high frequency).
  
  
  RESULTS
  Parental responses affirmed prenatal smoke exposure in 16.2% of 964 adolescents. Prenatal smoke exposure was associated with elevated pure-tone hearing thresholds at 2 and 6 kHz (P < .05), a higher rate of unilateral low-frequency SNHL (17.6% vs 7.1%; P < .05) in bivariate analyses, and a 2.6-fold increased odds of having unilateral low-frequency SNHL in multivariate analyses (95% CI, 1.1-6.4) after controlling for multiple hearing-related covariates.
  
  
  CONCLUSIONS
  Prenatal smoke exposure is independently associated with higher pure-tone hearing thresholds and an almost 3-fold increase in the odds of unilateral low-frequency hearing loss among adolescents. These novel findings suggest that in utero exposure to tobacco smoke may be injurious to the auditory system.
authors.affiliation: Department of Pediatrics, New York University School of Medicine, New York, USA. michael.weitzman@nyumc.org
authors.forename: Michael
authors.initials: M
authors.lastname: Weitzman
authors.forename: Nandini
authors.initials: N
authors.lastname: Govil
authors.forename: Ying Hua
authors.initials: YH
authors.lastname: Liu
authors.forename: Anil K
authors.initials: AK
authors.lastname: Lalwani
mesh_terms: D000293:Adolescent; D000328:Adult; D001301:Audiometry, Pure-Tone; D016009:Chi-Square Distribution; D003367:Cotinine / Q000097:blood; D003430:Cross-Sectional Studies; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000453:epidemiology*; D006801:Humans; D016015:Logistic Models; D008297:Male; D009749:Nutrition Surveys; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D014481:United States / Q000453:epidemiology
chemical_list: D014028:Tobacco Smoke Pollution; D003367:Cotinine