Varying Impact of Gestational Diabetes Mellitus on Incidence of Childhood Cancers: An Age-Stratified Retrospective Cohort Study
Research Design & Methods: We conducted a retrospective cohort study of 1 million children born between 2006 and 2019 in Quebec, Canada. We identified children who were exposed to gestational diabetes in utero and followed them from birth up to 14 years of age to identify new onset cancers. We estimated hazard ratios (HR) for the association between gestational diabetes and childhood cancer using Cox proportional regression models adjusted for covariates through inverse propensity score weights.
Results: A total of 83,626 children (8.2%) were exposed to gestational diabetes and 1,702 developed cancer during 7.6 million person-years of follow-up. Children exposed to gestational diabetes had a higher risk of any cancer (HR 1.19, 95% CI 1.01-1.40), with signals present for blood cancer (HR 1.27, 95% CI 0.92-1.76) and solid tumors (HR 1.14, 95% CI 0.94-1.40). The association between gestational diabetes and cancer was strongest early in life and decreased with age. Gestational diabetes was associated with 1.47 times the risk of any cancer (95% CI 1.21-1.79), 1.44 times the risk of solid cancer (95% CI 1.12-1.87), and 1.61 times the risk of blood cancer (95% CI 1.09-2.36) in children under 2 years. Gestational diabetes was not significantly associated with blood or solid cancers after 2 years of age and all associations disappeared after 6 years.Conclusions: Hyperglycemia may be carcinogenic in utero and may be a novel risk factor for early childhood cancer.