Faculty of Veterinary Medicine research featured on cover of Environmental Science & Technology

“Amniotic fluid contains numerous unknown chemicals with hormone-like activity”

The baby in a mother’s womb is exposed to a diverse range of man-made chemicals we continuously introduce into our environment, researchers at the Faculty of Veterinary Medicine of Utrecht University demonstrated in a study that was published in the December issue of the authoritative American journal Environmental Science & Technology. PhD candidate Hanna Dusza and Professor of Toxicology Juliette Legler developed a robust methodology to characterise foetal exposure to a wide spectrum of Endocrine Disrupting Compounds (EDCs) in amniotic fluid. This method can be used to identify unknown EDCs, and to further study how exposure to these compounds in a mother’s womb may affect children’s health. The research is an important step forward in the field of endocrine disruptor research.

In the last decades hundreds if not thousands of synthetic, man-made chemicals have been produced and introduced into our environment. These include a wide range of compounds from parabens in personal care products, pesticides in crops and foods, brominated flame retardants in furniture, phthalates and bisphenols in plastics, and many more chemicals in numerous industrial and consumer products. The general population, including pregnant women, are exposed on a daily basis to a wide variety of these chemicals, and there is growing scientific evidence for their adverse effects on human health. 

Interfering with natural hormones

Our old beliefs that the placenta forms a barrier for these contaminants have now been replaced with sound scientific evidence to the contrary, with a variety of environmental pollutants detected in umbilical cord blood, placenta, amniotic fluid and meconium. Early life exposure to EDCs is of specific concern. “They can interfere with the body’s endocrine system, for example by blocking or mimicking natural hormones, and therefore may disrupt developmental processes tightly regulated by hormonal signalling”, says senior author Juliette Legler. The developing baby in the mother’s womb is especially vulnerable to the exposure to these compounds and the effects of such early life exposure have been linked to increased incidence of cancer, diabetes and obesity, as well as other developmental, reproductive, and neurological effects that can manifest long after birth. 

Repository for environmental pollutants

“The research on prenatal exposure to environmental pollutants and the contribution of these compounds to the developmental origins of disease is still in its infancy”, says lead author Hanna Dusza. “We don’t know what many of these chemicals are and what effects they may have on the developing foetus. The fact that amniotic fluid is a repository for many environmental pollutants, can be obtained non-invasively and is in direct contact with the foetus, makes it an ideal matrix to study prenatal exposure.” 
Dusza developed a novel method to identify chemicals with biological activity in amniotic fluid. “We extracted a wide variety of environmental pollutants in amniotic fluid and tested the extract on specifically engineered cells that produce light when exposed to chemicals that bind to hormone receptors, such as estrogen and androgen receptors. We found a high production of light in the cells, indicating chemicals with hormone-like activity.” They also detected EDCs from different chemical classes, such as parabens, triclosan, PFAS, dioxins, bisphenol A (BPA) and its alternative bisphenol S (BPS), confirming their passage through the placenta and exposure of the baby in the womb. 

“This study shows that the developing baby is exposed to more compounds with potential endocrine disrupting activity than we ever knew before”

Other chemicals

Dusza: “What was really surprising, was that the observed activity could not be fully explained by the presence of natural hormones in the amniotic fluid, and the known EDCs measured in this study hardly contributed to the overall response observed in our cell tests. This means that the remaining hormone-like response may come from other diverse (unidentified) chemicals or their metabolites. In our current research, we are trying to uncover the compounds that are responsible for the remaining activity.”
Legler: “This study shows that the developing baby is exposed to more compounds with potential endocrine disrupting activity than we ever knew before. It is essential to identify these unknown EDCs in order to determine their risk to baby’s health, and to take steps to reduce exposures.”

There are plenty of ways for pregnant women and the general population to reduce exposure to harmful environmental pollutants. For advice on avoiding exposure to endocrine disruptors, see the following websites:
•    https://www.endocrine.org/topics/edc/what-you-can-do
•    https://www.edc-free-europe.org/how-to-avoid-edcs
•    https://www.nrdc.org/stories/9-ways-avoid-hormone-disrupting-chemical

For more information on endocrine disruptors see the following website: https://echa.europa.eu/hot-topics/endocrine-disruptors