Tobacco and Public Health - TCSC Indonesia

JONATHAN M. SAMET 299
Fetal effects. Researchers have demonstrated that active smoking by mothers during
pregnancy results in a variety of adverse health effects in children, postulated to result
predominantly from transplacental exposure of the fetus to tobacco smoke components
and reduced oxygen delivery (US Department of Health and Human Services 2001).
Maternal smoking during pregnancy reduces birth weight (US Department of Health
and Human Services 2001) and increases risk for SIDS, an association considered
causal in the recent WHO consultation and by the United Kingdom’s Scientific
Committee on Tobacco (Scientific Committee on Tobacco and Health & HSMO 1998).
Secondhand smoke exposure of nonsmoking mothers is associated with reduced birth
weight as well, although the extent of the reduction is far less than that for active
maternal smoking during pregnancy. In a meta-analysis, the summary estimate of the
reduction of birth weight associated with paternal smoking was only 28 g (Windham
et al. 1999), compared with about 200 g for maternal smoking.
Health effects on the child postnatally, resulting from either secondhand smoke
exposure to the fetus or to the newborn child, include SIDS, and adverse effects on
neuropsychologic development and physical growth. A number of components of
secondhand smoke may produce these effects, including nicotine and carbon monoxide.
Possible longer-term health effects of fetal secondhand smoke exposure include
increased risk for childhood cancers of the brain, leukemia, and lymphomas, among
others. In the WHO consultation (WHO 1999), the evidence on postnatal secondhand
smoke exposure and risk of SIDS was found to be insufficient to support a causal
conclusion. A meta-analysis of the evidence on childhood cancer through the time of
the 1999 consultation, subsequently reported elsewhere, did not show a significant
association of secondhand smoke exposure with overall risk for childhood cancer or
for leukemia (Boffetta et al. 2000).
Perinatal health effects. These health effects include reduced fetal growth, growth retardation,
and congenital abnormalities. In most studies, paternal smoking status has
been used as the exposure measure to assess the association between secondhand
smoke exposure and these nonfatal perinatal health effects. Low birth weight was first
reported in 1957 to be associated with maternal smoking (Simpson 1957), and maternal
cigarette smoking during pregnancy is considered to be causally associated with
low birth weight (US Department of Health and Human Services 1989). Recent studies
report lower birth weight for infants of nonsmoking women passively exposed to
tobacco smoke during pregnancy (Martin and Bracken 1986; Rubin et al. 1986).
Other nonfatal perinatal health effects possibly associated with secondhand smoke
exposure are growth retardation and congenital malformations, and a few studies
assessed fatal perinatal health effects. Martin and Bracken (1986) demonstrated a strong
association with growth retardation in their 1986 study, and several more recent studies
provide support (Zhang et al. 1992; Roquer et al. 1995). The few studies conducted to
assess the association between paternal smoking and congenital malformations
(Seidman et al. 1990; Savitz et al. 1991; Zhang et al. 1992) have demonstrated risks