P10-04 Primary and Oxidative DNA Damage from Prenatal Tobacco Exposure

Tobacco exposure during pregnancy remains a significant public health concern, associated with a wide range of adverse maternal and fetal outcomes. Understanding the role of genotoxicity mechanisms in mediating these effects is essential to elucidate how tobacco-related compounds compromise genomic integrity during fetal development. In the context of the NeoGene project, this study investigated the extent of primary and oxidative DNA damage in umbilical cord blood lymphocytes, employing the comet assay as a sensitive tool for detecting genotoxic effects. This cross-sectional study included pregnant women receiving prenatal care at a public hospital in Portugal. Maternal smoking status was validated through urinary cotinine levels measured by ELISA, while DNA damage in umbilical cord blood lymphocytes was assessed using the comet assay (the standard alkaline version for primary DNA damage and the FPG-modified version to detect oxidative lesions). Preliminary statistical analysis of the 361 cord blood samples analyzed to date (out of 595 collected in total) revealed a significant association between primary DNA damage and maternal smoking status (p<0.05). Although oxidative DNA damage levels were elevated in samples from smoking mothers, the difference did not reach statistical significance. Additionally, primary DNA damage varied significantly according to maternal educational level, suggesting a potential influence of socioeconomic factors on genotoxic risk. These findings seem to confirm that prenatal exposure to tobacco is associated with increased primary DNA damage in cord blood lymphocytes, underscoring the genotoxic risk to the developing fetus. The association with maternal educational level further suggests the influence of social and behavioral factors on exposure and vulnerability. The final analysis will offer a more comprehensive understanding of transplacental exposure to genotoxic agents, essential for developing effective strategies for early-life health promotion and disease prevention. This work was supported by FCT and FAPESP (FAPESP/19914/2014).