Smoking and pregnancy

Smoking is known to have an effect on the baby before it is born. Nicotine, carbon monoxide and other chemicals in tobacco smoke are passed on to the baby through the placenta.¹ Nicotine has a direct effect of increasing the heart rate of the baby and its breathing movements.¹ Some of the chemicals passed on to the baby through the mother's blood are known to cause cancer.²

During pregnancy, smokers have a greater risk of miscarriage and, during the birth, are more likely to have complications.³

The chances of the baby dying at birth or shortly after are increased if the mother has smoked during the pregnancy.³

The likelihood of having a low-weight baby increases if the mother smokes during her pregnancy. Babies born with a lower-than-average birth weight are more likely to get infections and have other health problems.⁴

Smoking by the father

Smoking by the father may result in lower birthweight of the baby and a higher risk of dying soon after birth. It is still to be established whether this result is due to the pregnant mother's passive smoking or from direct damage to the sperm.^{5, 6}

Smoking by parents

Recent research suggests that smoking by either the mother or the father during pregnancy is associated with a higher incidence of all childhood cancers combined.⁷ These findings should be considered as tentative and requiring more research.⁸

Smoking after birth

Smoking by the mother is considered to be one of the major risk factors for sudden infant death syndrome (SIDS or cot death).⁹

If the mother is breast feeding, nicotine from cigarettes is passed on to the baby through the milk and also through the air the baby breathes.¹ 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 snore and cough during the night, probably due to the long-term effect of breathing in tobacco smoke.¹¹

Exposure at home

Many Australian children are exposed to passive smoking in the home. Survey data shows that over 540,000 children aged four and under live in households with one or more smokers.¹² This is half of all children in this age group. Because we know that children are particularly sensitive to the health effects of passive smoking, this is cause for concern.

Long-term effects

The long-term effects of the mother smoking around her child may be impairment of learning, slower growth and changes to behaviour.^{3, 13}

References

1. US Department of Health and Human Services. The Health Consequences of Smoking: Nicotine Addiction. A report of the Surgeon General. Rockville, Maryland: US 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.
2. US Department of Health and Human Services. The Health Consequences of Smoking: Cancer. A report of the Surgeon General. Rockville, Maryland: US Department of Health and Human Services, Public Health Service. Office on Smoking and Health, 1982.
3. US Department of Health and Human Services. Reducing the Health Consequences of Smoking: 25 years of progress. A report of the Surgeon General, Rockville, Maryland: US 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.
4. US Department of Health and Human Services. The Health Consequences of Smoking for Women: A report of the Surgeon General. Rockville, Maryland: US Department of Health and Human Services, Public Health Service, Office of the Assistant Secretary for Health, Office on Smoking and Health, 1980.
5. Royal College of Physicians. Smoking and the Young: A report of a working party of the Royal College of Physicians. The Lavenham Press, 1992.
6. Davis DL. Paternal smoking and fetal health [letter]. The Lancet 1991;337:123.
7. John EM, Savitz DA, Sandler DP. Prenatal exposure to parents' smoking and childhood cancer. Am J Epidemiol 1991;133:123-132.
8. 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.
9. Southall DP, Samuels MP. Reducing the risks in sudden infant death syndrome [editorial]. Br Med J 1992;304:265-266.
10. Landau L. Annotations: passive smoking in childhood. Austr Paediatr J 1988;24:217-272.
11. Corbo GM, Fuciarelli F, Foresi A, De Benedetto F. Snoring in children: association with respiratory symptoms and passive smoking. Br Med J 1989;299:1491-4.
12. Australian Bureau of Statistics. National Health Survey 1995. Unpublished data.
13. Weitzman M, Gortmaker S, Sobol A. Maternal smoking and behaviour problems of children. Pediatrics 1992;90:342-349.