Your life before becoming a parent matters more than you think. New research suggests that before a child is conceived, parents’ exposure to any kind of environmental stressors can alter genes and harm their future child’s health, according to an article published in the journal Endocrinology.

A parent's exposure to environmental stressors, including malnutrition, psychological stress, and endocrine-disrupting chemicals may result in genetic reformations that can continue into future generations. Researchers found that when these genes were changed, the alterations led to a series of disadvantages later in life, including an increased risk of obesity, diabetes, and cognitive disorders. The article is the culmination of a conference on prenatal programming and toxicity, where more than 300 people attended and which featured over 60 oral presentations on chemical, physical, and biological stressors on the endocrine, immune, and nervous systems.

“In regard to environmental stressors, a good start lasts a lifetime,” said Dr. Philippe Grandjean, an author of the article and professor of environmental medicine at the University of Southern Denmark, in a statement. “Unfortunately, current testing paradigms do not properly assess the impact of risk factors during vulnerable exposure windows. Without new policies and guidelines, we cannot have a universal health start for children.”

Previous research focused on how parental environmental stressors impact the child during pregnancy and early childhood. The presentations emphasized that taking a look at those same stressors before conception could highlight a developmental window for both a mother and a father.

Further, the placenta’s role in fetal development and programming is especially important when considering the impact of these stressors. The placenta acts as an immune-endocrine organ that produces hormones and helps fetal growth. It can provide useful biomarkers which expose any greater risk that a future child may have.

Epigenetics is the study of chemical reactions and what factors influence them. In an article published in 2014, a researcher suggested that the transmission of genes was the result of epigenetics. The sequence of the DNA wasn’t changed, but the packaging was within mice that he had studied. The study was then transferred into a study of transgenerational effects in humans, specifically obese children. Although it has been difficult to find full links, the study shows there are connections in the transference of genes.

Source: Grandjean P, Barouki R, Bellinger D, et al. Life-Long Implications of Developmental Exposure to Environmental Stressors: New Perspectives. Endocrinology. 2015.