Exposure to organochlorine compounds during pregnancy and birth outcomes in the mother-child cohort in Crete, Greece (Rhea study)

摘要

Background: Several organochlorine compounds (OCs), including polychlorinated biphenyls (PCBs) and pesticides are persistent organic pollutants (POPs) that bioaccumulate through the food chain and cross the placenta. OCs have been shown to be developmental toxicants in animal experiments but the epidemiological evidence on pregnancy outcomes is inconsistent. Aims: We examined whether in utero exposure to 11 different OCs is associated fetal growth and gestational age in 1117 mother-child pairs of a prospective mother-child cohort in Greece. Methods: Concentrations of several PCBs and organochlorine pesticides (p,p-dichlorodiphenyl dichloroethene [p,p-DDE], p,p-dichlorodiphenyl trichloroethane [p,p-DDT], tetra-brpmodiphenyl ether [BDE-47], and hexachlorobenzene [HCB]) were determined in 1st trimester maternal serum by gas chromatography high resolution mass spectrometry. We constructed an overall exposure score based on the concentrations of each of four POPs or groups of POPs (HCB, DDE, BDE-47 and ΣPCBs) that took values from 0 (all chemicals below the median) to 4 (all chemicals above). Multiple linear regression models were used to investigate the associations with birth weight, gestational age, and head circumference. Results: A significant decrease in birth weight was observed for increasing levels of HCB (adjusted β= -72.5 g; 95% CI:-131.6 to -13.5) and ΣPCBs (adjusted β= -72 g; 95% CI:-141.5 to -2.4). These results were more pronounced in girls. A one-unit increase in the overall exposure score was also associated with lower birth weight (adjusted β= -30.2 g; 95% CI, -57.7 to -2.7). Small, negative but not statistically significant associations were observed between OCs, gestational age and head circumference. Conclusions: The findings suggest that prenatal exposure to PCB and HCB impairs fetal growth and add to the growing literature that demonstrates an association between low-level organochlorine exposure and fetal growth.