Are Your Baby Dreams Going Up in Smoke?

Presumably all parents-to-be want the best for their future children. Most have at least some awareness of the importance of prenatal care, that is, during pregnancy, and some even consider the impact of preconception care. People who find themselves experiencing difficult conceiving often learn more than the average intended parent about things that can be done to increase chances of a positive outcome. Often, lifestyle changes may be required to achieve pregnancy, and one very important change is avoiding smoking.

Smoking impacts fertility in a variety of ways

  • Chemicals in tobacco smoke can alter important reproductive hormones (such as estrogen, progesterone, and testosterone), creating an imbalance which may stand in the way of conception;
  • Those same chemicals can damage paternal chromosomes, leading to increased risk of early miscarriage due to genetic abnormality;
  • Often-undetected negative effects of smoking on maternal health, e.g. hypertensive vascular disease or severe metabolic disorders such as diabetes and thyroid dysfunction, can cause early miscarriage;
  • Vascular effects of smoking have been strongly linked to impotence;
  • Smokers appear to be at greater risk for ectopic (tubal) pregnancies and fallopian infection;
  • Smoking has been correlated with cervical-factor infertility, defined as a poor postcoital test (of cervical mucus) in the absence of infection.

Many studies have been conducted since the 1980 Surgeon General's report (U.S. DHHS, 1980) stated that "cigarette smoking appears to exert an adverse effect on fertility". Apparently, the related processes most affected by hormonal alterations (caused by tobacco smoke) would likely be ovulation and perhaps implantation.

While the exact reasons are still being uncovered, researchers now believe that smoking can create sub-fecundability, that is to say significantly delay conception. In addition, menopause begins as much as two or more years earlier in women who smoke, thought to be related to ovotoxins in cigarette smoke or to the effects of smoke on hormone regulatory mechanisms. Even when IVF is used as a means of bypassing some potential infertility factors caused by smoking, the use of tobacco is seen to negatively impact IVF outcome.

As more research is conducted and more is learned about how our bodies respond to toxins in our environment, the news for smokers can only get worse. While some physicians choose to take a quieter stand on the issue, even in cases of infertility and other disease, the evidence which is already in is enough to convince most infertile couples that, if conception is the primary goal, smoking is best avoided.

Bibliography

Ashley, M. J., M.D. Health effects of tobacco use, 1995.

F. Bolumar, J. Olsen, J. Boldsen, and the European Study Group on Infertility and Subfecundity (Department of Epidemiology and Social Medicine, Steno Institute of Public Health, Aarhus, Denmark). Smoking Reduces Fecundity: A European Multicenter Study on Infertility and Subfecundity. Am J Epidemiol 1996;143:578-87.

Cooper, Joel R. Smoking and Impotence, 1995.

Hall, C. T., Teen Males Who Smoke Risk Sperm Damage, San Francisco Chronicle, October 2, 1998.

Office of Environmental Health Hazard Assessment, California Environmental Protection Agency, Health Effects of Exposure to Environmental Tobacco Smoke, Chapter 5: Reproductive Effects, 1997.

Snyderman, Nancy, M.D., The Inconceivable Effects of Smoking on Fertility.

Somkuti, S. G., M.D., Ph.D., Environmental And Behavioral Factors Associated With Decreased Female Fertility, 1997.