DiscussionWe have found in this stu

Discussion
We have found in this study that exposure to ETS in pregnant
women was significantly associated with a higher risk of smallfor-gestation
birth. Several epidemiological studies have shown
similar effects. A meta-analysis of studies conducted before
mid-1995 reported an overall RR of 1.2 (95 % CI, 1.1 to 1.3)
for LBW at term or small-for-gestational age among the infants
born to mothers exposed to ETS during pregnancy.15 A
recent small, case-control study found an association of IUGR
with detectable nicotine level in mothers’ hair samples. With
non-smoking women whose hair nicotine concentrations were
in the lowest quartile as the reference group, the odds ratio
(OR) for small-for-gestational-age birth was increased among
women with concentrations in the upper and two middle quartiles
(ORs 2.1, 95% CI=0.4 - 10.1 and 3.4, 95 % CI=1.3 - 8.6
respectively).16 The reported results were not adjusted for
confounders, although the authors stated that several potential
confounders had no effect. There are some studies that
have utilized urinary cotinine levels as a biomarker of exposure
and found a higher risk of IUGR in babies born to mothers
exposed to ETS.