. 2016 Mar 1;193(5):486–494. doi: 10.1164/rccm.201510-2013PP

Table 1.

Comparison of the Effects of Maternal Smoking during Pregnancy and the Effects of Nicotine Exposure from Animal Models during Pregnancy on Lung Development and Function

Category	Effect	Smoke Exposure	Nicotine Exposure	Smoke Exposure References	Nicotine Exposure References
Pulmonary function	Decreased forced expiratory flow	Yes	Yes	30–36	48–50
	Decreased compliance^*	Yes	Maybe	37–39, 94	56
	Altered flow ratio^†	Yes	Unknown	32, 33
Respiratory illness	Increased airway reactivity/asthma/wheeze^‡	Yes	Yes	23, 31, 44, 82	48, 79–81
	Decreased arousal/increased apnea^§	Yes	Yes	86, 87, 95	88–90
	Increased respiratory infections/hospitalizations/altered immune function^\|\|	Yes	Yes	40–43	96–98
Anatomic and cellular changes	Increased connective tissue/airway wall thickening	Yes	Yes	59, 60, 99	56–58
	Increased narrow and smaller airways	Yes	Yes	55	48, 51, 52, 79
	Altered alveolar geometry	Yes	Yes	56, 61	62–64, 100
	Increased type 2 cells/surfactant	Yes	Yes	67, 68	52, 56, 65, 66
	Increased NEB/PNEC	Yes	Yes	69, 70, 94	56, 101, 102
Mechanistic underpinnings	Oxidative mechanisms underlying effects	Yes	Yes	32, 45, 46	49, 78
	Respiratory effects modified by nAChR SNPs/knockouts	Yes	Yes	32	48, 51, 52
	Modified levels of nAChR expression	Yes	Yes	60	56, 89, 91, 92
General	Decreased birth weight^¶	Yes	No	103, 104	49, 50, 103, 105, 106
General	Prematurity	Yes	Yes	103, 107	103, 108–110

Definition of abbreviations: nAChR = nicotinic acetylcholine receptor; NEB = neuroepithelial bodies; PNEC = pulmonary neuroendocrine cells; SNP = single-nucleotide polymorphism.

Most, though not all, studies show an effect. In animal studies there is a downward trend.

^{^†}

Ratio of time to peak tidal expiratory flow to expiratory time.

^{^‡}

In animal studies, increased airway reactivity is used as a surrogate for asthma and wheeze.

^{^§}

Correlates of increased risk of sudden infant death syndrome in offspring of smokers.

^{^||}

Alterations in immune function in animals used as a surrogate for hospital admissions.

^{^¶}

There is a downward trend in birthweight, but it is not statistically significant in most studies.