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Developmental Biology - Gestational Diabetes
PFAS, the 'Forever Chemicals'
PFAS move from mom to fetus at higher rate in gestational diabetes...
A University of Massachusetts Amherst environmental epidemiologist studying the presence of PFAS compounds in new mothers and their babies found that women with gestational diabetes had a "significantly higher" rate of transferring the synthetic chemicals to their fetus.
The newly published study in Environment International is among the largest to date in terms of the number of per- and polyfluoroalkyl substances (PFASs) examined - 17. Those particular compounds are among the PFAS chemicals associated with growing health concerns, including cancer risk, hormone interference, immune system suppression and developmental disruptions in infants and children.
Since the 1950s, PFAS compounds have been used worldwide in common household and industry goods, including nonstick cookware, water - and stain - resistant materials and food packaging. These "forever chemicals," so called because they do not break down in the environment, are also used in aqueous firefighting foams at military training sites and can infiltrate drinking water, which has become a major source of exposure in specific communities, including in Massachusetts.
"The contamination is all over the world. We find them [PFASs] even in polar bears."
Youssef Oulhote PhD, Assistant Professor of Biostatistics and Epidemiology, University of Massachusetts Amherst; and study corresponding author.
Blood and umbilical cord samples from 151 mother-newborn pairs in the Faroe Islands were examined by Oulhote and public health colleagues at Sorbonne University in Paris, the University of Southern Denmark, the Faroese Hospital System and Harvard University, where Oulhote began his research into the health effects of chemicals.
The Faroe Islands are located off the coast of Northern Europe, halfway between Norway and Iceland. The local population, which traditionally eats a lot of whale, is genetically and socioeconomically homogeneous, minimizing "confounding factors" in the research. "Most importantly, they consume whale, which is high in the food chain, so it accumulates many of the contaminants," Oulhote explains.
The study is the largest to date to model both the ratios of transplacental transfer and the patterns of transfer in the blood and plasma of multiple PFAS with different physical and chemical properties and different maternal and newborn characteristics.
While previous research has shown that PFAS compounds cross the placental barrier and reach the fetus, this study was the first to note the effects of gestational diabetes. "It's one of the most consistent results we got," Oulhote says. "There was up to a 50 percent greater transfer on average" in mothers with gestational diabetes. "We hypothesized that diabetes mellitus alters the kinetic disposition and metabolism of these chemicals. We know this has been shown to happen with some drugs and some nutrients in previous studies."
Researchers found that the transfer ratio depended on both physical and chemical structure of the compounds. Some PFAS compounds have been phased out since 2002 due to concerns about their toxicity. Newer PFAS compounds have shorter carbon chains and are assumed to be less toxic and accumulate less.
Highlights
• Per- and polyfluoroalkyl substances (PFASs) are a growing public health concern and can cross the placenta
• Data on transplacental transfer efficiency and partitioning of short and long chain PFASs in blood matrices are limited.
• We investigated predictors of transplacental transfer and blood partitioning of 17 PFAS in 151 mother-newborn pairs.
• We observed significantly higher transfer in mothers with gestational diabetes.
• Functional groups and carbon chain length were important predictors of transplacental transfer and blood partitioning.
Abstract
Background
Per- and polyfluoroalkyl substances (PFASs) are a growing public health concern. Some longer chain PFASs bioaccumulate and many compounds persist in the environment for long time periods. Recent studies have established their ability to pass through placenta, yet data on the transplacental transfer efficiency and partitioning of short and long chain PFASs in blood matrices are limited.
Objectives
To assess predictors of the partitioning of 17 PFAS compounds detected in the maternal serum, umbilical cord serum and whole cord blood samples from matched mother-newborn pairs from two Faroe Islands cohorts.
Methods
We examined 151 mother-newborn pairs from two successive Faroese birth cohorts. Cord:maternal serum (transplacental transfer) and serum:whole cord blood (blood partitioning) ratios were estimated for 17 PFAS compounds. We also examined the relationships of these ratios with maternal, newborns', and physico-chemical properties using multivariable regression analyses.
Results
Moderate to high correlations were observed between maternal and cord serum PFAS concentrations (?: 0.41 to 0.95), indicating significant transfer of these compounds from the mother to the fetus. Median transplacental transfer ratios were generally below 1, except for perfluorooctane sulfonamide (FOSA), and ranged between 0.36 for perfluorodecanoate (PFDA) and perfluoroundecanoate (PFUnDA) and 1.21 for FOSA. Most PFASs exhibited a preference to the serum component of the blood, except FOSA and perfluoroheptanoate (PFHpA), with blood partitioning ratios ranging from 0.36 for FOSA to 2.75 for PFUnDA. Both the functional groups and carbon chain length of different PFASs were important predictors of transplacental transfer and blood partitioning. We observed a U-shaped relationship between transplacental transfer ratios and carbon chain length for perfluorocarboxylates and perfluorosulfonates. Importantly, gestational diabetes was also a strong predictor of transplacental transfer ratios, with significantly higher transfer in mothers with gestational diabetes.
Conclusions
Our findings provide a better understanding of the transplacental transfer and blood partitioning of a large number of PFAS compounds. Results elucidate the importance of chemical structure for future risk assessments and choice of appropriate blood matrices for measurement of PFAS compounds.
Authors
Berrak Eryasa, Philippe Grandjean, Flemming, Nielsen, DamaskiniValvi, Denis Zmirou-Navier, Elsie Sunderland, Pal Weihe, Youssef Oulhote.
Acknowledgements
Financial support for this study came from the National Science Foundation, National Institutes of Environmental Health Sciences, Oceans and Human Health Program (OCE-1321612).
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Jul 31, 2019 Fetal Timeline Maternal Timeline News
 A study in gestational diabetes finds PFAs affect a mother's pregnancy. CREDIT Michael Geng PhD, Senior Research Officer.
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