A study performed to 482 Asturian mothers and their babies by researchers from the University of Oviedo has proven that weight gain by mothers during pregnancy plays a key role in the exposition of the fetus to organohalogenated compounds. Thus, experts have observed that the women who follow the requirements of weight gain during pregnancy can reduce the accumulation of persistent organic pollutants in their newborns, while those mothers who do not gain enough weight pass over a higher concentration.

Organohalogenated compouds (OHs) are highly resistant, toxic and lypophillic pollutants. They are present in many plastics, pesticides, insulation materials and also in the air. The exposition to such pollutants during the development of the fetus can negatively affect the functions of the thyroid and it may, therefore, increase the risk of adverse effects during childhood. Although the majority of these compounds have been subjected to studies for years, their transference during pregnancy is still relatively unknown.

A team led by Dr. Adonina Tardón García, Director of the Unit of Epidemiology of Cancer of the University Oncology Institute of the Principality of Asturias (IUOPA), has studied the exposition of the fetus to different families of OHs and their relation to the weight gain by the mother during pregnancy and with other socio-demographic features. To achieve this, they took samples from the mothers' serum, blood from the umbilical chord and the placenta to analyze the concentrations of OHs in each of them. The experts also analyzed the relations of concentration between paired samples.

The work by Dr. Tardón's team are part of the Childhood and the Environment project (INMA), funded by the Carlos III Health Institute. The prestigious specialized journals Environ Health Perspect and Environment International have already published he results of the study conducted by the University of Oviedo.

The tests performed to 482 Asturian mothers and their babies revealed that all the newborns presented detectable levels of these pollutants

Between 2004 and 2008, a total of 482 Asturian mothers and their newborns were subjected to the study. The team took samples from their blood, umbilical chord and placenta and analyzed the concentrations found in different Persistent Organic Compounds (organochlorites, polychlorofeniles and polychlorofenile ether). The results revealed that all the newborns presented detectable levels of the organohalogenated pollutants. The highest concentration belonged to the main metabolite of the DDT pesticide, which was found in 99,7% of the babies. In general terms, the concentrations of organochlorated compounds found where higher in the serum of the mother than in the placenta and the umbilical chord.

In terms of the relation between weight gain during pregnancy and the transmission of this type of compounds, the experts saw that the mothers that gained less weight during pregnancy transfered more organohalogenated compounds to their children at birth. The research took as their indicator of a suitable weight gain during pregnancy the guidelines established by the Institute of Medicine (IOM).

The study concludes that pre-birth life is that phase in human development that is the most sensitive to environmental pollutants, and an early exposition to Persistent Organic Compounds may increase the risk of suffering from health problems during childhood.

Dr. Tardón's research team now studies the effects that organochlorated compounds have in newborns and how they can affect their growth. The lines of research now open include the study of their impact on the hormonal development of the children and their possible interference with the capacity to absorb Vitamin D. Finally, the research analyzes where there is or not a link between childhood obesity and the presence in the body of persistent organic compounds.

Research Team

• Adonina Tardón García (Lead Researcher)
• Ana Fernández Somoano
• Ana Souto García
• Cristina Arias
• Isolina Riaño (San Agustín Hospital)
• Cristina Rodríguez Dehei (San Agustín Hospital)