BACKGROUND: Most studies of the reproductive consequences of cigarette smoking base exposure on self-reported smoking habits. This study examines the relationship of birth outcomes to the timing and intensity of maternal active and passive smoking estimated both from self-reports and from @entity4874 concentration in maternal urine during early, middle, and late gestation. METHOD: This cohort study included 740 white and Hispanic @entity1 who obtained antenatal care at the East Boston Neighborhood Health Center between 1986 and 1992. At each antenatal visit, information on maternal active and passive smoking was obtained by a detailed questionnaire, and by measurement of urine @entity4874 concentrations. @entity1 birth outcomes were obtained from hospital records. Multiple linear regression was used to evaluate antenatal smoking variables on birth outcomes, with adjustment for maternal demographic characteristics, reproductive history, @entity167 use, maternal weight and height, and @entity1 gender. RESULTS: The percentage of mothers who ever smoked cigarettes during pregnancy was 55.5% for white and 10.2% for Hispanic @entity1 . A significant inverse exposure-response relationship between @entity4874 concentration in maternal urine and @entity1 size at birth was demonstrated. However, the relationship was less clear between maternal self-reported smoking status and these outcomes. For the entire gestation, a 1000 ng increase in mean urine @entity4874 concentration was associated with a 59 +/- 9 g reduction in birthweight, a 0.25 +/- 0.05 cm reduction in length, and a 0.12 +/- 0.03 cm reduction in head circumference, respectively. For maternal passive smoking, the much smaller magnitude of effect precludes firm conclusions. CONCLUSIONS: These data suggest that preventing and reducing active maternal smoking during pregnancy may have a beneficial impact on @entity1 size at birth.

Maternal smoking during pregnancy, urine XXXX concentrations, and birth outcomes. A prospective cohort study.

@entity1 :: ('9606', 'Species') :: ['women', 'Infant', 'infant'] @entity167 :: ('CHEBI:16236', 'Chemical') :: ['alcohol'] @entity4874 :: ('MESH:D003367', 'Chemical') :: ['cotinine']
@entity4874 :: (MESH:D003367,Chemical) :: ['cotinine']
