In utero tobacco exposure: the effects of heavy and very heavy smoking on the rate of SGA infants in the Federal State of Saarland, Germany

Abstract

Objective: To assess the effects of heavy and very heavy smoking on the rate of small for gestational age (SGA) infants, and to assess socio-economic and regional differences in smoking patterns in pregnant women in Germany.

Study design: The Neonatal and Perinatal database of the federal state of Saarland, Germany was used to perform a population-based analysis of preterm (>32 weeks of gestation) and term (>36 weeks of gestation) newborns in 2004-2006. The rate of SGA babies dependent on the amount of tobacco exposure among self-identified smokers and non-smokers were assessed, and distinct maternal risk factors for smoking were evaluated. Our data were compared with the German National Perinatal database.

Results: 14,593 paired data sets (peripartum/perinatal) were included in this study. The overall rate of smoking during pregnancy was 11.8% with a high percentage of pregnant women smoking 11-20 cigarettes/day (heavy smoker; 4.0%), and >20 cigarettes/day (very heavy smoker; 0.6%). Self-identified heavy tobacco use significantly increased the risk for SGA infants (p<0.01) in women without uteroplacental insufficiency. Risk factors for smoking included ethnicity (German/Caucasian), socio-economic parameters (single vs. non-single households, status of employment) and age. Smoking pattern and the rate of SGA babies in our cohort differed substantially from the national average.

Conclusions: Although the overall rate of smoking appears comparable to previously published data, heavy and very heavy smoking was high in our cohort. Heavy smoking was disproportionately associated with SGA. Preventative measures and strategies should take into consideration socio-economic risk factors as well as regional differences, and should be targeted at distinct subgroups that are especially prone to smoking during pregnancy.