Measuring prenatal tobacco exposure in newborn blood spots
Initial Award Abstract
Research on the health effects of prenatal exposure to active and secondhand smoking during pregnancy is hampered by the inability to precisely measure active and secondhand smoking in pregnancy. This is one reason why the findings from retrospective studies of rare health problems, like birth defects, childhood cancer, and asthma have not agreed with one another. Generally these studies have asked mothers to recall their exposure to smoking or secondhand smoking during a pregnancy that occurred years earlier. Authors of the 2006 Surgeon General’s Report called for future research to stop using such methods and instead to begin using objective methods, such as biochemical measures, to precisely assess active and secondhand smoking in pregnancy.
We are proposing a study to evaluate the usefulness of measuring two groups of compounds, cotinine and tobacco-derived hemoglobin adducts in newborn dried blood spots, to precisely measure active and secondhand smoking in pregnancy. Cotinine is a metabolite of tobacco in humans that comes from nicotine found in cigarettes and has been used widely in research to measure levels of active and passive smoking in pregnancy. Tobacco derived hemoglobin adducts are red blood cells modified by different cancer causing chemicals in tobacco smoke. To date there have been a few small, yet promising, studies that have examined these compounds in dried newborn blood spots, specimens that are available for research purposes for nearly all babies born in California since 1982.
The proposed study will expand on these previous studies and make use of an existing sample of 433 newborns in San Diego County, among whom cotinine in umbilical cord blood and mid-pregnancy maternal blood has already been measured previously. We propose to measure cotinine and hemoglobin adducts in their stored newborn blood spots using the most sensitive laboratory methods currently available. We would like to know if the concentrations of cotinine and hemoglobin adducts in blood spots match up with what we found previously in cord and maternal blood.
This information will help us find out how cotinine and hemoglobin adducts in newborn blood spots can be used as biomarkers of prenatal tobacco exposure for future studies. These methods and specimens show promise to improve the quality of studies on the health effects of active and passive prenatal exposure to tobacco, on the historical trends in prenatal tobacco exposure since 1982, on prenatal tobacco exposure in California’s heterogeneous population, and on the success of tobacco control efforts in California. |