Tag Archives: smoking

Smoking affects fertility

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http://commons.wikimedia.org/wiki/Cigarette#mediaviewer/File:Papierosa_1_ubt_0069.jpeg
http://commons.wikimedia.org/wiki/Cigarette#mediaviewer/File:Papierosa_1_ubt_0069.jpeg

A recent study shows that smoking during pregnancy and breastfeeding may impair sons’ fertility.

We all know that smoking affects our health causing primary respiratory and cardiovascular problems. In pregnant women cigarette smoke can affect not only mom’s health but also child’s health, causing premature birth, growth retardation, miscarriages, reduced birth weight, and sudden infant death syndrome 1,2,3,4.

The team led by Professor Mc Laughlin at the University of Newcastle (New South Wales, Australia) published a study in Human Reproduction on the effect of maternal smoking using a mouse model 5. They exposed 27 female animals to cigarette smoking before, during, and after pregnancy and analyzed the the pups and the adult male mice. Smoking affected the viability of germ cells, the diameter of seminiferous tubules, and the morphology of neonatal testes in the pups. In the adult mice, germ cells showed DNA damage and Sertoli cell (cells that promote sperm cell development) showed aberrant function; these phenomena were accompanied by alteration in the expression of genes involved in several pathways, including spermatogenesis, oxidative stress, and Sertoli cell function. Furthermore mice from “smoking” mothers had fewer sperm with affected motility and fertilization ability (binding to the zona pellucida of the egg). This work is a comprehensive demonstration in a mouse model that maternal cigarette smoke compromises the fertility of the male offspring. Previous studies suggested the same effects but they were not conclusive.

When a woman gets pregnant, she receives many warnings on what she may or may not do. Some of these warnings are based off common sense, previous observational and epidemiological  studies or surveys, and the woman doesn’t really get an explanation of the precise consequences of her acts if she doesn’t follow the instructions—this is not always the case—but all she gets is a warning. In contrast, the consequences of cigarette smoke are known and are not short-term (miscarriage, reduced birth weight, etc.) but long-term consequences. The study described above is an accurate demonstration This study should really be a deterrent for pregnant women who are still smoking, that are around 13–20% in the United States(the reports are controversial) and 4–20% in Europe (depending on the country) 6. Further studies in the future may highlight other long-term damages and may focus on the damages of not only maternal smoke but also secondhand smoke.

 

1Perinatal complications associated with maternal tobacco use.Andres RL, Day MC. Semin Neonatol. 2000 Aug;5(3):231-41. Review.

2Revisiting the effect of maternal smoking during pregnancy on offspring birthweight: a quasi-experimental sibling analysis in Sweden. Juárez SP, Merlo J. PLoS One. 2013 Apr 17;8(4):e61734.

3Environmental tobacco smoke and risk of spontaneous abortion. George L, Granath F, Johansson AL, Annerén G, Cnattingius S. Epidemiology. 2006 Sep;17(5):500-5.

4Prenatal smoking among adolescents and risk of fetal demise before and during labor.Aliyu MH, Salihu HM, Alio AP, Wilson RE, Chakrabarty S, Clayton HB.J Pediatr Adolesc Gynecol. 2010 Jun;23(3):129-35Epidemiology. 2006 Sep;17(5):500-5.

5Damaging legacy: maternal cigarette smoking has long-term consequences for male offspring fertility.Sobinoff AP, Sutherland JM, Beckett EL, Stanger SJ, Johnson R, Jarnicki AG, McCluskey A, John JC, Hansbro PM, McLaughlin EA.Hum Reprod. 2014 Sep 30. pii: deu235.

6Characteristics of women who continue smoking during pregnancy: a cross-sectional study of pregnant women and new mothers in 15 European countries.Smedberg J, Lupattelli A, Mårdby AC, Nordeng H.BMC Pregnancy Childbirth 2014 Jun 25;14:213.

Smoking Increases the Risk of Estrogen Receptor Positive Breast Cancer

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A study from the Fred Hutchinson Cancer Center shows that smoking among young women may increase the risk of developing estrogen receptor (ER)-positive breast cancer, but not triple negative breast cancer (TNBC).

The group led by Dr. Christopher Li conducted a population-based study among women from 22 to 44 years old diagnosed with breast cancer between January 2004 and June 2010 in the July 2014. The patients were 938 women in the control group, 778 in the ER-positive group, and 182 in the TNBC group. The researchers interviewed the patients and obtained detailed information about different aspects of their lifestyle—reproductive history, demographics, physical activity, alcohol drinking, medical history—and smoking habits—regency, number of cigarettes smoked per day, ages when smoked. The patients were divided in never smokers and ever smokers (current or former). The ever-smoker group was further categorized based on the number of pack of cigarettes smoked per year.

Smokers had increased risk of developing breast cancer overall (30%), without any significative change when the total number of years of smoking or the age women first started were considered. Although the small number of TNBC cases, the risk was associated with ER-positive breast cancer and not with TNBC. However, among current smokers, women who had been smoking for more than fifteen years had 50% increased risk of developing ER-positive breast cancer compared with women who had been smoking for fewer years. Of note is that, in women who had not been smoking for more than ten years the risk of developing ER-positive breast cancer decreased dramatically.

Various studies have correlated smoking to the risk of breast cancer, but this is one of the few studies linking smoking to ER-positive breast cancers in premenopausal women. Metabolites of tobacco, found in the breast fluid and breast tissue of current smokers, have been shown to have an estrogenic effect in in vitro studies, thus explaining the increased risk of ER-positive breast cancer in young women found in this research.

Smoking has several adverse effects and has been associated to different cancers. This is not only a study that supports previous reports linking smoking to breast cancer, but this study links smoking to a specific subtype of breast cancer (ER-positive) in young women.

 

Masaaki Kawai, Kathleen E. Malone, Mei-Tzu C. Tang, Christopher I. Li. Height, body mass index (BMI), BMI change, and the risk of estrogen receptor-positive, HER2-positive, and triple-negative breast cancer among women ages 20 to 44 years. Cancer, 2014