During pregnancy, the fetus changes and grows. However, some changes to your infant DNA can affect your child’s health and not always for the better. DNA methylation is when there are epigenetic modifications made to your DNA which causes it to mutate and until recently, it was unclear if these mutations were permanent.

In a recent study conducted at the Columbia Center for Children's Environmental Health at the Mailman School of Public Health, it was discovered that DNA methylation happens prenatally and can affect infant health even after birth. Several factors can incuse DNA methylation, such as smoking, but other environmental causes can induce a change as well. Arsenic is known to be one environmental cause, but others include exposure to lead and air pollution as well. These DNA mutations are typically considered harmful and the researchers who led the study sought to establish how long these mutation would last.

Lead author Dr. Julie Herbstman, an assistant professor of Environmental Health Sciences at the Mailman School, said during the study that "the current dogma is that DNA methylation marks are set during early development and are mainly persistent thereafter. However, there were no data in humans to either support or refute this hypothesis. We set out to fill this data gap.”

The health impact of small DNA methylation is not clear, but larger changes can be tracked. The study included 279 participants who were part of the Center's Mothers & Newborns study in Northern Manhattan and the South Bronx. After delivery, the cord blood from the children was collected analyzed, and 165 children had their blood retested three years later as well.

The research team found that the cord blood methylation reliably predicted the level of methylation in the children’s blood three years later, which led the team to conclude that DNA methylation changes that occur early in life or prenatally can affect children in the future as well.

One thing that the researchers noticed during the study was that the mother’s BMI played an important role in DNA methylation. Mothers with a higher BMI before pregnancy had children with lower levels DNA methylation at birth and three years after birth.

The research team says that the study successfully proved that genetic mutation during pregnancy lasts beyond birth, but the fact that the mother’s BMI played a role in the levels of DNA methylation needs further research.

Source: Columbia University's Mailman School of Public Health (2013, September 4). DNA changes during pregnancy persist into childhood. ScienceDaily.