Prenatal tobacco exposure: Developmental outcomes in the neonatal period.

Abstract

Smoking during pregnancy is a persistent public health problem that has been linked to later adverse outcomes. The neonatal period-the first month of life-carries substantial developmental change in regulatory skills and is the period when tobacco metabolites are cleared physiologically. Studies to date mostly have used cross-sectional designs that limit characterizing potential impacts of prenatal tobacco exposure on the development of key self-regulatory processes and cannot disentangle short-term withdrawal effects from residual exposure-related impacts. In this study, pregnant participants (N ϭ 304) were recruited prospectively during pregnancy, and smoking was measured at multiple time points, with both self-report and biochemical measures. Neonatal attention, irritable reactivity, and stress dysregulation were examined longitudinally at three time points during the first month of life, and physical growth indices were measured at birth. Tobacco-exposed infants showed significantly poorer attention skills after birth, and the magnitude of the difference between exposed and nonexposed groups attenuated across the neonatal period. In contrast, exposure-related differences in irritable reactivity largely were not evident across the 1st month of life, differing marginally at 4 weeks of age only. Third-trimester smoking was associated with pervasive, deleterious, dose-response impacts on physical growth measured at birth, whereas nearly all smoking indicators throughout pregnancy predicted level and growth rates of early attention. The observed neonatal pattern is consistent with the neurobiology of tobacco on the developing nervous system and fits with developmental vulnerabilities observed later in life.

Detecting Graded Exposure Effects: A Report on an East Boston Pregnancy Cohort

“…In neither dataset did lighterexposed and nonexposed groups differ, likely refl ecting the higher prevalence in the lTE group of women who quit smoking or smoked very few cigarettes in the latter half of pregnancy when the fetus puts on substantial body mass. In contrast, the s-FCM method yielded different results for body length and head circumference for the two datasets, but this difference refl ects the mixed fi ndings more broadly in the literature (e.g., Conter et al, 1995 ;Espy et al, 2011 ;Nelson et al, 1999 ).…”

“…Specifi cally, we hypothesize that as in MIDS, three subgroups will be identifi ed: ( a) heavier, ( b) lighter , and ( c) nonexposed and that these groups, particularly the heavier versus nonexposed groups, will differ in fetal growth outcomes. Since mixed results exist in the literature as to the signifi cance of exposure effects on neonatal body length and head circumference (e.g., Conter, Cortinovis, Rogari, & Riva, 1995 ;Espy et al, 2011 ;Hardy & Mellits, 1972 ;Nelson, Jodscheit, & Guo, 1999 ), these effects may differ in MISSEB and MIDS.…”

“…Typically, the amount of exposure is quantifi ed by comparing groups defi ned by a predetermined cut-score of the number of cigarettes or level of cotinine, for example, collected at a certain time in cross-sectional studies. However , smoking has varying and complex patterns across pregnancy, as many women underreport smoking, and smoking behavior across pregnancy varies substantially (e.g., Espy et al, 2011 ;Pickett, Rathouz, Kasza, Wakschlag, & Wright, 2005 ). Characterizing the degree of prenatal tobacco exposure is thus a signifi cant challenge but an important step if researchers are to detect more nuanced exposure effects on offspring.…”

Developmental Consequences of Fetal Exposure to Drugs: What We Know and What We Still Must Learn

“…There is also a greater likelihood of exposed infants to be admitted into the neonatal intensive care unit relative to unexposed controls (Adams et al, 2002). Newborns exposed in utero to nicotine are more irritable and have poorer attention than unexposed infants, and they exhibit hypertonicity, increased tremors and startle responses, and deficient speech processing as well (Espy et al, 2011;Key et al, 2007;Mansi et al, 2007;Reijneveld et al, 2002;Stroud et al, 2009a). Within the first month of life, exposed infants show signs of poorer self-regulation and require more handling by caregivers (Stroud et al, 2009b).…”

“…For this review, we will provide an overview of some of the findings pertaining to neurobehavioral outcomes. At birth, exposed infants tend to be smaller in body weight, height, and head circumference, effects attributable to third and possibly second trimester exposure (Espy et al, 2011;Himes et al, 2013). There is also a greater likelihood of exposed infants to be admitted into the neonatal intensive care unit relative to unexposed controls (Adams et al, 2002).…”