Despite concerted efforts by researchers and health care professionals, maternal smoking during pregnancy remains a serious public health problem. Approximately 20% - 30% of pregnant women use tobacco during pregnancy. Many of these women quit during pregnancy and another proportion reduce their tobacco use.
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Impact on Health
Smoking in pregnancy results in serious risks for both the woman and the fetus. Cigarette smoking by pregnant girls and women has been shown to increase risks of complications in pregnancy and to cause serious adverse fetal outcomes including low birth weight, still births, spontaneous abortions, decreased fetal growth, premature births, placental abruption, and sudden infant death syndrome (SIDS). Other reproduction related effects of smoking include lower estrogen levels leading to early menopause and links to infertility.
Quitting smoking during pregnancy has considerable positive health impact for both women and fetuses, and reduces health problems for children born of mothers who smoke.
- Quit Smoking Telephone Counselling Protocol for Pregnant and Postpartum Women
Pre- and Postnatal Smoking Issues
How Are Unborn Babies Affected?
- Smoking is known to have an effect on babies before they are born. Nicotine, carbon monoxide and other chemicals in tobacco smoke are passed on to the baby through the placenta.1
- Nicotine increases a baby's heart rate and breathing movements. Some of the chemicals passed on through the mother's blood are known to cause cancer.2
- During pregnancy, smokers have a greater risk of miscarriages. During the birth, they are more likely to have complications.3 The chances of a baby's dying at birth or shortly thereafter are increased if the mother has smoked during pregnancy.3
- Babies of women who smoked or were exposed to second-hand tobacco smoke during pregnancy are, on average, smaller at birth than babies of non-smoking mothers. Smoking mothers give birth to infants who weigh about 150 grams less at term than non-smokers. 1, 3 Babies born with a lower-than-average birth weight are more likely to get infections and have other health problems.4
- A clear relationship exists between the number of cigarettes smoked during pregnancy and a slowdown in the growth of the fetus. 1, 3 These babies are more prone to perinatal complications, illnesses and death.
- Nursing mothers who smoke can pass along harmful chemicals from cigarettes to their babies in breast milk. But it is important to note that a smoker's breast milk is still better than formula, in regards to a baby's development.
- More than 18% of all deaths from Sudden Infant Death Syndrome (SIDS) are due to maternal tobacco use.9
- Even in later years, children of mothers who smoked during pregnancy tend to be slightly shorter than other children and have more difficulty with reading, mathematics and related skills.5
- It has not yet been determined if male smoking damages the sperm, thereby contributing to low birthrates and higher infant mortality rates.5, 6
- Babies of smokers are more likely to suffer from asthma and other respiratory infections than those of non-smokers.10
- Children exposed to tobacco smoke are more likely to cough during the night, probably due to the long-term effect of breathing in tobacco smoke.11
- The long-term effects of parental smoking around children may be impaired learning, slower growth and changes in behaviour.3,12
- U.S. Department of Health and Human Services. The Health Consequences of Smoking: Nicotine Addiction. A Report of the Surgeon General. Rockville, Maryland: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, Center for Health Promotion and Education, Office on Smoking and Health, 1988.
- Environmental Protection Agency. Respiratory Health Effects of Passive Smoking: Lung Cancer and Other Disorders. Washington: Environmental Protection Agency, Office of Research and Development, Office of Air and Radiation, 1992. Publication No. EPA/600/6-90/006F.
- U.S. Department of Health and Human Services. Reducing the Health Consequences of Smoking: 25 years of progress. A Report of the Surgeon General, Rockville, Maryland: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health, 1989.
- U.S. Department of Health and Human Services. The Health Consequences of Smoking for Women: A report of the Surgeon General. Rockville, Maryland: U.S. Department of Health and Human Services, Public Health Service, Office of the Assistant Secretary for Health, Office on Smoking and Health, 1980.
- California Environmental Protection Agency. Health Effects of Exposure to Environmental Tobacco Smoke. Final Report. Sacramento: California Environmental Protection Agency, Office of Environmental Health Hazard Assessment, 1997.
- Davis, D.L. Paternal smoking and fetal health [letter]. The Lancet 1991;337:123.
- John, E.M., Savitz, D.A., Sandler, D.P. Prenatal exposure to parents' smoking and childhood cancer. Am. J. Epidemiol. 1991;133:123-132.
- Pershagen, G., Ericson, A., Otterblood-Olausson, P. Maternal smoking in pregnancy: does it increase the risk of childhood cancer? Int. J Epidemiol. 1992;21:1-5.
- Southall, D.P., Samuels, M.P. Reducing the Risks in Sudden Infant Death Syndrome [editorial]. Br. Med. J. 1992;304:265-266.
- U.S. Department of Health and Human Services. Reducing Tobacco Use: A Report of the Surgeon General. Atlanta, Georgia: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health, 2000.
- Corbo, G.M., Fuciarelli, F., Foresi, A., De Benedetto, F. Snoring in children: association with respiratory symptoms and passive smoking. Br. Med. J. 1989;299:1491-4.
- Weitzman, M., Gortmaker, S., Sobol, A. Maternal smoking and behaviour problems of children. Pediatrics 1992;90:342-349.