Longitudinal assessment of PCBs and chlorinated pesticides in pregnant women from Western Canada

Abstract

BackgroundMaternal exposures to organochlorines prior to pregnancy are considered a risk to neonatal welfare, specifically in relation to neurocognitive functions. There is growing interest in the evaluation of maternal blood testing as a marker for fetal exposure as well as the variable geographic distribution of these priority chemicals.MethodsThree hundred and twenty-three women in the second trimester of pregnancy entered the study at a prenatal clinic providing genetic counselling information. Subjects who had an indication for genetic amniocentesis based on late maternal age were eligible to participate. Two hundred and thirty-eight completed an environmental questionnaire. A sample of amniotic fluid was taken for karyotype analysis in 323 women and blood samples during pregnancy (209), at birth (105) and from the umbilical cord (97) and breast milk (47) were also collected. These samples were tested for 29 PCB congeners and organochlorine pesticides.ResultsThe concentrations of PCB 153 in these media were relatively low in relation to other studies. Σ PCBs measurements in samples taken during the second trimester of pregnancy, at birth and in the umbilical cord were strongly correlated. Specific measurements of PCB 153 and PCB 180 among those subjects with completed sampling of blood samples from mothers and cord samples were significantly correlated. The concentrations of PCBs and pesticides did not differ in relation to prior spontaneous abortion history. There were no organochlorines present in the amniotic fluid at the current level of quantification.ConclusionPregnant women from the Western Canada region of Calgary, Alberta are exposed to relatively low concentrations of organochlorines. Measurement of maternal blood during the second trimester of pregnancy can reliably estimate the fetal exposure to PCBs. This estimate is reliable for Group 2 and 3 PCBs as well as PCB 153 and PCB 180. The amniotic fluid does not contain measurable concentrations of pesticides and PCBs under the conditions of the levels of quantification.

Maternal Serum Polychlorinated Biphenyl Concentrations across Critical Windows of Human Development

“…To this end, we believe our longitudinal cohort study is the first to provide empirical data regarding mean changes in serum concentrations of PCBs from the preconception-to-postnatal window of human development. A few previous investigators have assessed the stability of select PCB congeners across trimesters of clinically established pregnancies and reported them to be highly correlated (Longnecker et al 1999), as do investigators comparing maternal concentrations during established clinical pregnancies with cord or postnatal concentrations (Ayotte et al 2003; Jarrell et al 2005). However, such correlation coefficients cannot be adjusted for time intervals or other relevant covariates.…”

Association of serum concentrations of persistent organic pollutants (POPs) and risk of pre-eclampsia: a case–control study

“…For research about pollutants in pregnant women it should be noted, because of different trends of POPs in each trimester of pregnancy [28, 29], the investigation of POPs within a pregnancy should be limited to one trimester for a more accurate evaluation. Meanwhile, previous studies reported that breastfeeding is one of the main routes for pollutants excretion [30, 31] and breastfeeding has a significant effect on decreasing the levels of organochlorine pesticides and PCBs in serum [32].…”

Polychlorinated biphenyls (PCBs) alter DNA methylation and genomic integrity of sheep fetal cells in a simplified in vitro model of pregnancy exposure

“…Anzalone et al Toxicology in Vitro 46 (2018) 39-46 the placenta (Foster et al, 2000;Jarrell et al, 2005). It is easier to discover some PCB metabolites than congeners (Gallenberg et al, 1990;Grimm et al, 2015).…”