Smoking during pregnancy is fraught with sudden death of infants

When conducting experiments on laboratory rats, McMaster University scientists identified a mechanism explaining how exposure to even small or moderate doses of nicotine on a developing fetus impairs the ability of newborns to respond to lack of oxygen (hypoxia episodes).

Tobacco smoke contains a lot of different compounds, but the authors found that it is nicotine that has a direct effect on the ability of certain cells to respond to lack of oxygen. If an infant, for example, turns face down in the crib, he should feel the lack of oxygen and move his head, but in children exposed to nicotine in the womb, this mechanism does not function properly.

During childbirth, the baby experiences a lack of oxygen, which stimulates the release of "stress hormones" by the adrenal glands – catecholamines, including adrenaline. These hormones ensure the removal of water from the lungs, "force" the child to take the first breath and contribute to a more efficient work of the heart. During the maturation of the body, the nervous system takes control of the release of catecholamines, but within a few months after birth, the adrenal glands independently perform the functions of an oxygen sensor that regulates the behavior of the child and his respiratory reactions during periods of apnea (temporary respiratory arrest) and asphyxia (suffocation). However, the ability of the adrenal glands to release catecholamines at such critical moments for adaptation to life outside the uterus is impaired when exposed to nicotine.

Portal "Eternal youth" www.vechnayamolodost.ru based on the materials of ScienceDaily.

06.02.2008