AbstractsMedical & Health Science

Smoking cessation in pregnancy

by Raoul A. Walsh

Institution: University of Newcastle
Degree: PhD
Year: 1994
Keywords: smoking; smoking cessation; pregnancy; low birthweight; perinatal mortality; neonatal mortality; spontaneous abortion
Record ID: 1031963
Full text PDF: http://hdl.handle.net/1959.13/1039132


Research Doctorate - Doctor of Philosophy (PhD) Smoking during pregnancy has been associated with many adverse pregnancy outcomes. However, debate continues about whether smoking causes these outcomes. Chapter 1 reviews the evidence that smoking is a cause of adverse pregnancy outcomes. The criteria of causation proposed by Bradford Hill (1966) are examined in relation to four outcomes: low birthweight, perinatal and neonatal mortality, spontaneous abortion and long-term developmental effects. The review found that the relative risk of having a low birthweight baby is nearly doubled in women who smoke during pregnancy compared with non-smoking women and that the relative risks of spontaneous abortion and perinatal and neonatal mortality are increased by about one-third. The magnitude of the long-term effects of maternal smoking on the physical and mental development of the offspring is small but measurable. The epidemiologic evidence associating maternal smoking with major adverse pregnancy outcomes in prospective and case-control studies displays a high degree of consistency. A dose-response gradient for smoking during pregnancy has not been clearly shown in relation to perinatal and neonatal mortality. However, there is strong support for a dose-response gradient in relation to low birthweight and spontaneous abortion and moderate support for long-term developmental effects. Although a biological causal mechanism has not been clearly delineated, considerable evidence indicates that the chemicals in tobacco smoke are capable of producing deleterious changes in the placenta and fetus. In addition to support for a causative role in the four outcomes examined in detail, the chapter also presents evidence that smoking in pregnancy increases the risk of other adverse outcomes including ectopic pregnancy, antepartum haemorrhage and Sudden Infant Death Syndrome. The findings support the importance of the goal of smoking cessation in pregnancy as a means of reducing the pregnancy-related burden of illness in the community. Chapter 2 examines the effectiveness of smoking cessation programs in pregnancy. A review of the literature located 20 controlled evaluations of smoking cessation interventions in pregnancy. The studies were rated using the methodological criteria outlined by Windsor and Orleans (1986). Twelve of the studies were judged methodologically inadequate and excluded from the review. The remaining studies were found to support the efficacy of cognitive behavioural smoking cessation programs in pregnancy. There was insufficient evidence to determine whether advice, feedback or nurse home-visitation programs increased smoking cessation rates in pregnancy under ideal conditions. None of the methodologically adequate cognitive behavioural studies fulfilled the criteria necessary for a smoking cessation program to be incorporated into routine antenatal care. In public antenatal settings, the prevalence of smoking is high and usual care providers have the greatest opportunity to intervene with smoking women.…