The list of the negative effects of cigarette smoking continues to grow. Cigarette smoke, be it first hand, second hand, or even third hand cigarette smoke has documented negative effects on women’s health, children’s health and the health of unborn babies. The latest news to be added onto the list is the effect of the cigarette smoke on the fetus’s thyroid function.
Second Hand Cigarette Exposure Affects Thyroid Function in Pregnant Women
When exposed to cigarette smoke either as active or passive smokers, people generally show lower levels of serum thyrotrophic (TSH) when compared to non-smokers. The source of the cigarette smoke does not matter. Even the thyroids of women exposed to second hand smoke (passive smoke) are affected (Giorgos S. Metsios, et al., “A Brief Exposure to Moderate Passive Smoke Increases Metabolism and Thyroid Hormone Secretion”, The Journal of Clinical Endocrinology & Metabolism Vol. 92, No. 1 208-211).
Cigarette Smoke Affects the Thyroid Function of Both the Mother and Her Unborn Baby
The effect was also found to be true in pregnant women (Beverley Shields et al, “Cigarette smoking during pregnancy is associated with alterations in maternal and fetal thyroid function”, Journal of Clinical Endocrinology & Metabolism, December 2008). In a study that compared thyroid hormones in a group of pregnant women (both smokers and non-smokers), the results showed that not only did smoking change the thyroid function of the mothers but it also decreased the levels of TSH in the fetus's blood
Abnormal Thyroid Hormones and Fetus Development
The thyroid gland is important in the regulation of metabolism and also affects growth rate and the rate of function of other body systems. Fetuses during weeks 10 to 12 of gestation develop a functioning thyroid. If thyroid hormone deficiency occurs during fetal development, severe and permanent neuronal damage can occur. In some cases this can lead to cretinism and severe mental retardation. (Haddow JE, Palomaki GE, Allan WC, et al. “Maternal thyroid deficiency during pregnancy and subsequent neuropsychological development of the child.” N Engl J Med. 1999;341:549-555.
It is Never to Late to Quit Smoking
According to "Cigarette Smoking in Pregnant Women" study, when some of the mothers stopped smoking during their pregnancy, their thyroid hormone levels returned to the same levels as of that of the mothers who were non-smokers. This to the scientists implied that the effect of the cigarette smoke on the thyroid were reversible. The United States National Toxicology Program’s Center for the Evaluation of Risks to Human Reproduction (CERHR) provides an informative webpage on “Common Concerns Related to Smoking and Fertility”. The page also has a list of tips to help pregnant women stop smoking.
