- In the past several decades, rates of delayed childbearing have increased, and as a result, maternal age has advanced. Our objective was to evaluate whether advanced maternal age is independently associated with an increased risk of childhood cancers in the offspring. A retrospective cohort study of women who delivered between the years 1991 and 2014 was conducted. Elderly parturients (≥ 35 years) were divided into two sub-categories: 35–39 and 40–50 years. The comparison group consisted of parturients aged 20–34 years. All hospitalizations of offspring up to the age of 18 years involving malignant morbidity were compared between the groups. A Kaplan-Meier survival curve was used to compare cumulative malignant morbidity incidence of the offspring. A Weibull regression model was used to control for confounders. During the study period, 201,738 deliveries met the inclusion criteria. Of them, 16.3% (n = 32,804) occurred in mothers aged 35 years or more (35–39 years old n = 26,145, 79.7%; 40–50 years old n = 6659, 20.3%). In the Weibull regression model, advanced maternal age exhibited no association with general malignant morbidity in the offspring up to 18 years of age (mothers aged 35–39: adjusted HR 1.06, 95% CI 0.76–1.48, p = 0.727; mothers aged 40–50: adjusted HR 0.73, 95% CI 0.36–1.46, p = 0.373). For leukemia, the regression model exhibited an independent association in maternal ages of 35–39 (adjusted HR 2.23, 95% CI 1.34–3.69, p = 0.002).