Spector Logan G, Hecht Stephen S, Ognjanovic Simona, Carmella Steven G, Ross Julie A
Division of Epidemiology/Clinical Research, Department of Pediatrics, University of Minnesota, 420 Delaware Street, Southeast, MMC 715, Minneapolis, MN 55455, USA.
Cancer Epidemiol Biomarkers Prev. 2007 Sep;16(9):1902-5. doi: 10.1158/1055-9965.EPI-07-0230.
Maternal smoking while pregnant is a plausible risk factor for childhood cancers because many seem to initiate in utero and tobacco-specific carcinogens cross the placenta. Social desirability bias may affect maternal report of smoking in case-control studies and could explain inconsistently observed associations with offspring cancer. Detection of tobacco smoke biomarkers in dried blood spots (DBS), which are increasingly stored by newborn screening programs, may improve retrospective assessment of fetal tobacco exposure. As proof-of-principle, we examined cotinine in DBS of 20 infants enrolled in a pilot study of pregnancy among low-income women. We recruited 107 pregnant women (<30 weeks of gestation) from six Women, Infants, and Children clinics in Minneapolis and St. Paul in 1999. Blood samples obtained at enrollment were tested for total cotinine using gas chromatography/mass spectrometry. Women were then interviewed at 7 months of gestation to determine current smoking habits. DBS were obtained from the Minnesota Department of Health. We tested DBS from 10 infants whose mothers had detectable serum cotinine at baseline and 10 control infants whose mothers had none. One quarter of each DBS was assayed for cotinine using gas chromatography/mass spectrometry; levels were estimated assuming 50 muL blood per sample. Mean cotinine was 29 ng/mL (SD, 7.5), 45 ng/mL (SD, 9.7), and 9 ng/mL (SD, 7.4), respectively, among infants of all smokers, infants of four women who acknowledged smoking at 7 months of gestation, and infants of nonsmokers. These results suggest that DBS analysis may identify infants of women who smoke throughout pregnancy.
孕期母亲吸烟可能是儿童癌症的一个风险因素，因为许多儿童癌症似乎始于子宫内，且烟草特有的致癌物可穿过胎盘。在病例对照研究中，社会期望偏差可能会影响母亲对吸烟情况的报告，这或许可以解释为何观察到的与子代癌症的关联并不一致。新生儿筛查项目越来越多地保存干血斑（DBS），检测其中的烟草烟雾生物标志物可能会改善对胎儿烟草暴露的回顾性评估。作为原理验证，我们检测了20名参加低收入女性孕期试点研究的婴儿干血斑中的可替宁。1999年，我们从明尼阿波利斯和圣保罗的六家妇女、婴儿和儿童诊所招募了107名孕妇（妊娠<30周）。入组时采集的血样用气相色谱/质谱法检测总可替宁。然后在妊娠7个月时对这些女性进行访谈，以确定她们当前的吸烟习惯。干血斑取自明尼苏达州卫生部。我们检测了10名母亲基线血清可替宁可检测到的婴儿以及10名母亲血清可替宁检测不到的对照婴儿的干血斑。每份干血斑的四分之一用气相色谱/质谱法检测可替宁；假设每份样本血量为50微升来估算水平。在所有吸烟者的婴儿、4名在妊娠7个月时承认吸烟的女性的婴儿以及非吸烟者的婴儿中，可替宁平均水平分别为29纳克/毫升（标准差7.5）、45纳克/毫升（标准差9.7）和9纳克/毫升（标准差7.4）。这些结果表明，干血斑分析可能识别出整个孕期吸烟女性的婴儿。
