Does maternal obesity influence risk of childhood cancer?

A new analysis by investigators from the University of Pennsylvania suggests that development of cancer in childhood may be influenced by early-life exposure to maternal obesity. The findings are based on a review of data from more than 1.8 million births in Pennsylvania.

Published in the American Journal of Epidemiology, the analysis looked at births and childhood cancers from 2003 through 2016, representing nearly 14 million person-years at risk. Of the children included, 2,352 were diagnosed with any cancer and 747 with leukemia before age 14 years.

The authors tested the hypothesis that birth certificate-derived maternal anthropometric characteristics were associated with increased risk of subsequent childhood cancer development, accounting for established maternal and infant risk factors. They found a 57% higher leukemia risk in children whose mothers had a body mass index (BMI) ≥ 40 (95% CI, 12-120). Birthweight 30% or more than expected was associated with a 2.2-fold higher risk of childhood cancer and 1.8-fold higher risk of leukemia compared with that in children born at the expected size. 

Newborn size did not mediate the association between maternal obesity and childhood cancer. The results, the authors said, “suggest a significant role of early-life exposure to maternal obesity-and fetal growth-related factors in childhood cancer development.”