Nicotine Exposure During Gestation: From Placental Dysfunction to Long-Term Neurobehavioral Outcomes.
BACKGROUND Prenatal nicotine exposure (PNE) remains a significant public health concern due to persistent tobacco use, electronic nicotine delivery systems, and second-hand exposure during pregnancy. Epidemiological and experimental evidence has demonstrated that nicotine can readily cross the placenta, disrupt placental development, and interfere with tightly regulated processes of fetal organogenesis. These early perturbations are increasingly recognized as initiating a cascade of structural, functional, and molecular alterations that extend beyond gestation and influence health trajectories across the lifespan. However, existing studies are often compartmentalized by developmental stage, limiting mechanistic integration across prenatal, natal, postnatal, and later-life outcomes. METHODS This review aims to (i) synthesize evidence from placental biology, developmental toxicology, neurobiology, and epigenetics to propose an integrated, life-course cascade model of PNE; (ii) delineate how nicotine-induced placental dysfunction and fetal hypoxia during prenatal development transition into structural, physiological, perinatal autonomic, and cardiorespiratory vulnerability, contributing to adverse birth outcomes and increased risk of sudden infant death syndrome; and (iii) examine how early disruption of nicotinic acetylcholine receptor mediated signaling alters neuronal differentiation, synaptic maturation, neuroimmune interactions, and stress-response pathways, leading to persistent cognitive, behavioral, and psychiatric susceptibility in postnatal life and adulthood. Emerging evidence for epigenetic reprogramming, sex-specific vulnerability, and intergenerational transmission, including paternal contributions, is also evaluated. RESULTS Evidence synthesized across placental biology, developmental toxicology, neurobiology, and epigenetics supports a cascade in which nicotine-induced placental dysfunction and fetal hypoxia contribute to structural, physiological, perinatal autonomic, and cardiorespiratory vulnerability, adverse birth outcomes, and increased risk of sudden infant death syndrome. Early disruption of nicotinic acetylcholine receptor-mediated signaling is associated with alterations in neuronal differentiation, synaptic maturation, neuroimmune interactions, and stress-response pathways, contributing to persistent cognitive, behavioral, and psychiatric susceptibility in postnatal life and adulthood. Emerging evidence also supports roles for epigenetic reprogramming, sex-specific vulnerability, and intergenerational transmission, including paternal contributions. CONCLUSION By integrating temporally distinct findings into a unified mechanistic framework, this review identifies critical developmental windows and molecular targets for intervention. Such an approach is essential for advancing preventive strategies, informing public health policy, and mitigating the long-term and transgenerational consequences of nicotine exposure.