The Role of Nicotine in the Effects of Maternal Smoking during Pregnancy on Lung Development and Childhood Respiratory Disease. Implications for Dangers of E-Cigarettes

Abstract

Use of e-cigarettes, especially among the young, is increasing at near-exponential rates. This is coupled with a perception that e-cigarettes are safe and with unlimited advertising geared toward vulnerable populations, the groups most likely to smoke or vape during pregnancy. There is now wide appreciation of the dangers of maternal smoking during pregnancy and the lifelong consequences this has on offspring lung function, including the increased risk of childhood wheezing and subsequent asthma. Recent evidence strongly supports that much of the effect of smoking during pregnancy on offspring lung function is mediated by nicotine, making it highly likely that e-cigarette use during pregnancy will have the same harmful effects on offspring lung function and health as do conventional cigarettes. In fact, the evidence for nicotine being the mediator of harm of conventional cigarettes may be most compelling for its effects on lung development. This raises concerns about both the combined use of e-cigarettes plus conventional cigarettes by smokers during pregnancy as well as the use of e-cigarettes by e-cigarette-only users who think them safe or by those sufficiently addicted to nicotine to not be able to quit e-cigarette usage during pregnancy. Thus, it is important for health professionals to be aware of the risks of e-cigarette usage during pregnancy, particularly as it pertains to offspring respiratory health.

Keywords: asthma; lung development; nicotinic receptor; pulmonary function.

Figure 1.

Prenatal nicotine exposure increases α7 nicotinic acetylcholine receptors (nAChRs), collagen, and trichrome staining in a parallel manner (56, 57). (A) α7 nAChR immunoreactivity (red) in lung from control 134-day fetal monkey. Magnification, ×100. (B) α7 nAChR immunoreactivity (red) in lung from nicotine-exposed 134-day fetal monkey. Magnification, ×100. (C) Collagen III immunostaining of control 134-day fetal monkey lung. Magnification, ×100. (D) Collagen III immunostaining of nicotine-treated 134-day fetal monkey lung. Magnification, ×100. (E) Masson trichrome–stained control 134-day fetal monkey lung. Magnification, ×100. (F) Masson trichrome–stained nicotine-exposed 134-day fetal monkey lung. Magnification, ×100. (G) Trichrome-stained human lung from infant who had sudden infant death syndrome whose mother smoked during pregnancy. Magnification, ×200. Reprinted by permission from Reference . A = airway; aw = airway; c = cartilage; carti = cartilage; V = vessel.