| Smoking during Pregnancy Affects Speech-Processing Ability
in Newborn Infants Alexandra P.F. Key,1 Melissa Ferguson,2 Dennis L. Molfese,3 Kelley Peach,2 Casey Lehman,2 and Victoria J. Molfese4 1Kennedy Center for Research on Human Development and Department of Hearing and Speech Sciences, Vanderbilt University, Nashville, Tennessee, USA; 2Department of Psychological and Brain Sciences, University of Louisville, Louisville, Kentucky, USA; 3Birth Defects Center, Department of Molecular, Cellular and Craniofacial Biology, University of Louisville, Louisville, Kentucky, USA; 4College of Education and Human Development, University of Louisville, Louisville, Kentucky, USA Abstract
Background: Tobacco smoking during pregnancy is known to adversely affect development of the central nervous system in babies of smoking mothers by restricting utero–placental blood flow and the amount of oxygen available to the fetus. Behavioral data associate maternal smoking with lower verbal scores and poorer performance on specific language/auditory tests. Objectives: In the current study we examined the effects of maternal smoking during pregnancy on newborns' speech processing ability as measured by event-related potentials (ERPs) . Method: High-density ERPs were recorded within 48 hr of birth in healthy newborn infants of smoking (n = 8) and nonsmoking (n = 8) mothers. Participating infants were matched on sex, gestational age, birth weight, Apgar scores, mother's education, and family income. Smoking during pregnancy was determined by parental self-report and medical records. ERPs were recorded in response to six consonant–vowel syllables presented in random order with equal probability. Results: Brainwaves of babies of nonsmoking mothers were characterized by typical hemisphere asymmetries, with larger amplitudes over the left hemisphere, especially over temporal regions. Further, infants of nonsmokers discriminated among a greater number of syllables whereas the newborns of smokers began the discrimination process at least 150 msec later and differentiated among fewer stimuli. Conclusions: Our findings indicate that prenatal exposure to tobacco smoke in otherwise healthy babies is linked with significant changes in brain physiology associated with basic perceptual skills that could place the infant at risk for later developmental problems. Key words: ERP, evoked potentials, newborn, prenatal, smoking, speech. Environ Health Perspect 115:623–629 (2007) . doi:10.1289/ehp.9521 available via http://dx.doi.org/ [Online 28 November 2006]
Address correspondence to A.P.F. Key, Kennedy Center for Research On Human Development, 21st Ave. S & Edgehill Ave., MRL Building, Rm. 231, Vanderbilt University, Nashville, TN 37203 USA. Telephone: (615) 322-3498. Fax: (615) 322-8236. E-mail: sasha.key@vanderbilt.edu This work was supported in part by grants from the Department of Health and Human Services (90XA0011) , National Institutes of Health (R01 HD17860) , and the U.S. Department of Education (R215K000023) to D.L.M. and V.J.M. The authors declare they have no competing financial interests. Received 17 July 2006 ; accepted 27 November 2006.
The full version of this article is available for free in HTML or PDF formats. |
