Oxidative damage and cholinesterase activity in maternal and umbilical cord blood from an agricultural region in southern Brazil.

Pesticide exposure during pregnancy, particularly to organophosphates and carbamates, has been associated with oxidative stress imbalance and adverse maternal and neonatal outcomes. This study aimed to evaluate cholinesterase activity and oxidative stress biomarkers in maternal peripheral blood and umbilical cord blood from mother and newborn pairs residing in an agricultural region of southern Brazil with environmental pesticide exposure. A total of 98 third-trimester pregnant women were recruited. Biomarkers of oxidative stress (MDA, GST, protein carbonyls, and 8-OHGua) and cholinesterase activity (AChE and BChE) were assessed in maternal and cord blood at delivery. Sociodemographic, clinical, and behavioral data were also collected. AChE activity was significantly reduced in cord blood (0.305 ± 0.15 μmol/min/mg) compared to maternal blood (0.612 ± 0.27 μmol/min/mg; p < 0.0001), with inhibition observed in 95% of neonatal samples. Elevated 8-OHGua levels were detected in 87% of maternal and 90% of neonatal samples. GST activity was significantly reduced in 65% of cord samples (p = 0.0001). Exploratory MCA analyses identified association patterns between biomarkers and maternal or neonatal variables. In cord blood, low birth weight showed the highest contribution in Dimension 3 (32.6%), followed by normal GST activity (20.9%). However, no significant associations were observed between biomarkers and major perinatal outcomes. The findings suggest relevant biochemical alterations in the maternal-newborn dyad, involving cholinesterase inhibition and oxidative imbalance. However, the absence of direct pesticide quantification requires cautious interpretation of the findings.