New European research has found that environmental factors that a woman is exposed to while pregnant, such as where she lives and even the outdoor temperature, could affect her baby's risk of having high blood pressure during childhood.
Led by researchers at the Barcelona Institute for Global Health (ISGlobal), the new study looked at data gathered from 1,277 mother-child pairs in the United Kingdom, France, Spain, Lithuania, Norway and Greece.
The children were aged between six and 11 and had no previous health problems, but at the time of the examination 10 percent of the children could be classified as hypertensive (having high blood pressure) or prehypertensive, a warning sign that an individual may develop high blood pressure.
The researchers looked at 89 prenatal maternal exposures and 128 postnatal child exposures, including exposures to air pollution, built environment (where the mother was living during pregnancy), fish intake, meteorology, natural spaces, traffic, noise, chemicals, and lifestyles.
The findings, published in the Journal of the American College of Cardiology, showed that mothers who lived in a walkable environment during their pregnancy, with access to green spaces, public transport and shops and restaurants, were more likely to have children with normal blood pressure.
The researchers proposed that the lower blood pressure resulted from the higher amount of physical activity that mothers engaged in during pregnancy.
They also found that exposure to a higher outdoor temperature during the time of the blood pressure assessment was associated with lower diastolic blood pressure in children.
On the other hand, exposure to chemicals such as bisphenol-A (BPA) (commonly found in plastic) and perfluorooctanoate (PFOA) (found in cosmetics, household cleaners or clothing) during pregnancy was linked with higher blood pressure in children. Children who had been exposed to copper during childhood also had a higher blood pressure.
Both low and high fish intake during pregnancy were associated with higher blood pressure in children, with the researchers explaining that although the omega-3 fatty acids in fish are beneficial for overall cardiovascular health, eating fish contaminated by chemicals or metals could reduce the positive effects of these omega-3 fatty acids.
Although the team noted that the study has several limitations, such as a small sample size, they add that the findings still highlight that environmental exposures early in life could have an important impact on a child's blood pressure.