Maternal obesity may raise child’s cancer risk

Babies born to mothers who have obesity are more likely to develop cancer in early childhood, a new study reports.

Using Pennsylvania birth records, researchers found a correlation between pre-pregnancy body-mass index (BMI) in mothers and subsequent cancer diagnosis in their offspring, even after correcting for known risk factors, such as newborn size and maternal age. The study appears in the American Journal of Epidemiology.

“Right now, we don’t know of many avoidable risk factors for childhood cancer,” says lead author Shaina Stacy, postdoctoral scholar in the University of Pittsburgh Public Health epidemiology department and the Hillman Cancer Center. “My hope is that this study can be, in a way, empowering and also motivating for weight loss.”

Researchers pored through nearly 2 million birth records and about 3,000 cancer registry records filed in Pennsylvania between 2003 and 2016 and found that children born to mothers who have severe obesity—BMI above 40—had a 57 percent higher risk of developing leukemia before age 5. Weight and height also individually associated with increased leukemia risk.

Further analysis showed that it wasn’t simply that larger women were giving birth to larger babies or that heavier women tended to be older—known risk factors for childhood cancer—but rather, a mother’s size independently contributed to her child’s risk.

The researchers think the root cause of the effect they’re seeing has something to do with insulin levels in the mother’s body during fetal development, or possibly changes to the mother’s DNA expression that passes to her offspring.

Importantly, not all levels of obesity carry the same risk. Among the women with obesity in the study, higher BMI came with higher cancer rates in their children. So, even small amounts of weight loss can translate to a real reduction in risk, Stacy says.

“We are dealing with an obesity epidemic in this country,” says senior author Jian-Min Yuan, professor of epidemiology and co-leader of the cancer epidemiology and prevention program at the Hillman Cancer Center.

“From a prevention point-of-view, maintaining a healthy weight is not only good for the mother, but also for the children, too.”

Additional authors are from the University of Pittsburgh and the Pennsylvania Department of Health. The National Cancer Institute and the Arnold Palmer Endowment Fund funded the work.

Source: University of Pittsburgh