We compared exposure to environmental in the third month of pregnancy. Variable All subjects District Prachatice Teplice Ethnicity European Romani Non-IUGR IUGR Non-LBW LBW Pregnancy outcome: IUGR Pregnancy outcome: LBW Pregnancy month 1 2 3 4 5 6 7 8 9 Table 2. 8-OxodG levels in placental DNA of all analyzed samples and in subgroups by district, ethnicity, and pregnancy outcome. n 891 297 594 749 142 750 141 762 129 Mean ± SD 2.11 ± 1.31 2.06 ± 1.33 2.14 ± 1.30 2.09 ± 1.31 2.23 ± 1.35 2.08 ± 1.30 2.29 ± 1.34 2.07 ± 1.28 2.37 ± 1.46 8-OxodG/105 dG Median (range) 1.80 (0.20–6.50) 1.76 (0.21–6.50) 1.81 (0.20–6.43) 1.80 (0.20–6.50) 1.81 (0.27–6.13) 1.74 (0.20–6.50) 2.03 (0.29–6.17) 1.75 (0.20–6.50) 2.25 (0.27–6.28) aFor comparison of medians by the Mann–Whitney U test. Table 3. Concentrations of PM2.5 during pregnancy for non-LBW and LBW subjects. Concentration of PM2.5 (µg/m3) Mean ± SD 28.8 ± 12.8 29.2 ± 12.6 30.2 ± 13.6 29.3 ± 13.7 29.2 ± 12.7 29.5 ± 13.8 26.2 ± 13.6 30.3 ± 16.0 28.5 ± 14.0 Non-LBW Median (min, max) 26.2 (1.13, 84.6) 26.5 (1.09, 82.4) 27.2 (1.09, 84.6) 26.0 (1.13, 86.1) 26.8 (1.13, 84.5) 26.4 (3.25, 86.1) 26.2 (3.25, 84.8) 25.8 (3.83, 86.1) 25.1 (1.09, 84.8) Mean ± SD 33.2 ± 13.1 33.6 ± 12.6 32.6 ± 13.6 31.3 ± 11.4 33.4 ± 14.8 30.4 ± 12.3 29.7 ± 13.3 30.6 ± 13.7 29.6 ± 13.4 LBW Median (min, max) p-Valuea 30.2 (11.0, 72.6) 32.1 (12.4, 72.6) 30.2 (8.02, 83.6) 30.0 (10.6, 64.6) 31.0 (11.0, 82.4) 27.0 (10.6, 84.6) 25.9 (4.48, 76.3) 26.2 (9.94, 80.5) 26.2 (5.99, 73.8) Abbreviations: max, maximum; min, minimum. aComparison of PM2.5 concentrations between non-LBW and LBW subjects using the Mann–Whitney U test. Table 4. Results from univariate logistic regression of haplotypes in the promoter region of MBL2 modifying the incidence of LBW. Haplotype Non-LBW (n) ATAATCCGCT/ATAATCCGCT 471 Other combinations 291 ATAATCCGCT/ GCGGAATAGA GCGGAATAGA/ GCGGAATAGA ATAATCCGCT/ ACGGAATAGA ap-Value estimated using logistic regression analysis. 268 LBW (n) 56 73 Crude OR (95% CI) Reference 2.11 (1.45–3.08) Rossner et al. non-IUGR samples, respectively; p = 0.055). LBW was associated with significantly higher oxidative DNA damage (median 8-oxodG levels/105 dG = 2.25, range, 0.27–6.28; median 8-oxodG levels/105 dG = 1.75, range, 0.20–6.50 for LBW and non-LBW samples, respectively; p < 0.05). pollutants during the individual months of pregnancy for IUGR and non-IUGR as well as LBW and non-LBW subjects. Although no significant differences were observed for IUGR and non-IUGR newborns exposed to both B[a]P and PM2.5 (data not shown) or for LBW and non-LBW children exposed to B[a]P (data not shown), LBW-affected children were exposed to higher concentrations of PM2.5 during the first to fifth months of pregnancy (Table 3). The concentrations of B[a]P during the individual months of pregnancy for all sub- jects and separately for mothers living in the Prachatice and Teplice districts are shown in Supplemental Material, Table 2 (doi:10.1289/ ehp.1002470). The corresponding data for PM2.5 are reported in Supplemental Material, Table 3. The levels of air pollutants were sig- nificantly higher in the Teplice district for all periods, with the exception of the B[a]P levels To test our hypothesis, we first performed univariate analyses of selected variables (e.g., SNPs, oxidative stress, air pollution, lifestyle, socioeconomic and other factors, and preg- nancy outcomes). The list of genes and SNPs significantly associated with LBW after cor- rection for multiple comparisons is shown in Supplemental Material, Table 4 (doi:10.1289/ ehp.1002470). We found four genes that mod- ified the incidence of LBW: the gene encod- ing MBL2, chemokine (C-C) motif ligand 7 (CCL7), C-C motif ligand 11 (CCL11), and C-C motif ligand 18 (CCL18). For the MBL2 p-Valuea 0.280 0.272 0.055 < 0.05 0.000 0.000 0.035 0.021 0.004 0.148 0.606 0.389 0.183 p-Valuea < 0.001 gene, we detected 10 SNPs associated with an increased risk of LBW. These SNPs, located in the promoter region of the MBL2 gene, formed three haplotypes with frequencies of 77.7% (haplotype ATAATCCGCT), 22.1% (haplo- type GCGGAATAGA), and 0.2% (haplotype ACGGAATAGA). The homozygous combi- nation ATAATCCGCT/ATAATCCGCT found in 59.1% of subjects was prevalent. Other combinations of haplotypes were detected in 40.9% of placental DNA samples. Table 4 summarizes the estimated effect of haplotypes in the promoter region of MBL2 on the LBW risk. Subjects not carrying the prevailing homozygous combination of the ATAATCCGCT haplotype were at signifi- cantly higher risk of LBW. We also identified genes and SNPs significantly associated with IUGR as well as 8-oxodG levels. However, after FDR correction, these associations were no longer evident (data not shown). Using univariate analysis, we further investi- gated the effect of exposure to B[a]P and PM2.5 during pregnancy on 8-oxodG levels. 8-OxodG levels in placental DNA was not affected by B[a]P (data not shown), whereas PM2.5 expo- sure during the second month of pregnancy was significantly associated with 8-oxodG levels in placental DNA [odds ratio (OR) = 1.68; 95% confidence interval (CI), 1.28–2.19; p < 0.001]. In univariate analyses, 8-oxodG levels in placental DNA were significantly associ- ated with IUGR (OR = 1.47; 95% CI, 1.02–2.12; p = 0.037; Table 5), but not with LBW (Table 6). Other factors associ- ated with IUGR included ethnicity, maternal BMI, maternal smoking, and the mother’s and father’s length of education (Table 5). Exposure to PM2.5 was not associated with IUGR (data not shown). District, ethnicity, sex and gestational age of the child, mater- nal BMI, smoking, marital status, and vita- min intake during pregnancy, paternal length of education and smoking, and exposure to PM2.5 in the first month of pregnancy were among variables associated with the risk of LBW (Table 6). B[a]P exposure affected nei- ther IUGR nor LBW (data not shown). The findings from multivariate-adjusted logistic regression investigating the fac- tors associated with IUGR are reported in Table 5. The results indicate that 8-oxodG levels remained the only variable significantly associated with the risk of IUGR (OR = 1.57; 95% CI, 1.06–2.34; p = 0.026). Factors asso- ciated with LBW after multivariate adjust- ment include 8-oxodG levels (OR = 1.83; 95% CI, 1.12–3.00; p = 0.017), sex (OR = 1.96; 95% CI, 1.21–3.18; p = 0.006), gesta- tional age (OR = 0.05; 95% CI, 0.03–0.11; p < 0.001), maternal smoking (OR = 0.52; 95% CI, 0.29–0.91; p = 0.023), and the hap- lotype in the MBL2 gene (OR = 2.59; 95% CI, 1.59–4.20; p < 0.001) (Table 6). ovlume 119 | number 2 | February 2011 • Environmental Health Perspectives