Maternal smoking during pregnancy and childhood obesity: results from the CESAR Study.

Childhood obesity is a worldwide public health concern. Recent studies from high income countries have demonstrated associations between maternal smoking during pregnancy and children's excess body weight. We examine associations between maternal smoking during pregnancy and children's overweight or obesity, in six countries in the less affluent Central/Eastern European region. Questionnaire data were analysed, for 8,926 singleton children aged 9-12 years. Country-specific odds ratios for effects of maternal smoking during pregnancy on being overweight, and on obesity, were estimated using logistic regression. Heterogeneity between country-specific results, and mean effects (allowing for heterogeneity) were estimated. Positive associations between maternal smoking and overweight were seen in all countries but Romania. While not individually statistically significant, the mean odds ratio was 1.26 (95% CI 1.03-1.55), with no evidence of between-country heterogeneity. Obese children were few (2.7%), and associations between obesity and maternal smoking during pregnancy were more heterogeneous, with odds ratios ranging from 0.71 (0.32-1.57) in Poland to 5.49 (2.11-14.30) in Slovakia. Between-country heterogeneity was strongly related to average persons-per-room, a possible socioeconomic indicator, with stronger associations where households were less crowded. Estimates of dose-response relationships tended to be small and non-significant, even when pooled. Our results provide evidence of a link between maternal smoking in pregnancy and childhood overweight. Associations with obesity, though strong in some countries, were less consistent. Maternal smoking may confer an addition to a child's potential for obesity, which is more likely to be realised in affluent conditions.

Down syndrome in births near landfill sites.

OBJECTIVES: The aim of the study was to examine the risk of giving birth to a child with Down syndrome associated with residence near landfill sites in England and Wales. METHODS: A 2-km zone around 6289 landfill sites processing special (hazardous), non-special and unknown waste type was used to indicate exposure. Postcodes within the 2-km zone were classified as 'exposed' and people living beyond 2 km comprised the reference population. Health outcome data were Down syndrome registrations from a national registry including 21 cytogenetic laboratories in England and Wales, for the years 1989 to 1998. With a Bayesian regression model, we calculated relative risks for the population living within 2 km of landfill sites relative to the reference population, assuming a common relative risk for all landfill sites. Adjustments were made for major confounders. RESULTS: There were 4640 cases of Down syndrome within 2 km of a landfill site. We found no excess risks of Down syndrome related to landfill sites. Adjustment for socio-economic status (SES) did not influence our estimates. There were no differences in risk between hazardous waste sites and other landfill sites. CONCLUSION: We found no excess risk of Down syndrome in populations living near landfill sites.