This comprehensive and informative review of the physiologic effects of nicotine on mothers and fetuses cites key studies and statistics revealing both the pervasive, injurious effects of smoking, and incentives for breaking the habit. Fifteen percent continue to smoke throughout pregnancy. Nicotine, the chief alkaloid in tobacco, directly stimulates acetylcholine receptors primarily located in the autonomic ganglion, adrenal medulla, and neuromuscular junctions releasing a multitude of vasoactive catecholamines and peptides. It is metabolized in the liver where over 20 metabolites have been identified. The effects of nicotine are seen in every trimester from spontaneous abortions in first trimester to premature delivery and decreased birthweight in the third.
Smoking reduces fertility, a problem which can be reversed after breaking the addiction.
Smoking results in respiratory problems in the baby because nicotine interferes with normal construction of microvilli and other basic structures of the lungs. Nicotine interferes with formation of elastic tissue leading to emphysema-like rigidity of the neonatal lungs. Mental and behavioral problems from nicotine exposure include attention deficit disorder, lower scores in expressive language and conceptual comprehension, smaller heads and lower height, and compromised arterial blood flow in the brain. Passive smoke exposure significantly adds to the effects of the mother s smoking alone. By P.S. Blair, P.J. Fleming, D. Bensley, I. Smith, C. Bacon, E. Taylor, J.G. Berry and J. Tripp.