Maternal weight during pregnancy and risk of childhood acute lymphoblastic leukemia in offspring

Abstract

Maternal exposures during pregnancy are critical for leukemogenesis in offspring since childhood leukemia often originates in utero. We conducted a population-based cohort study in Sweden to investigate the association between the risk of acute lymphoblastic leukemia (ALL) in offspring and maternal anthropometrics during pregnancy, including gestational weight gain (GWG) and maternal weight and body mass index (BMI) in early pregnancy and before delivery. A total of 2 964 813 live-born singletons during 1983–2018 were included and followed from birth to ALL diagnosis, age 18, or 2018. Standardized incidence ratios (SIRs) were calculated to compare the risk of ALL in different exposed groups. 1 446 children were diagnosed with ALL, of whom 55.3% were boys. We observed an increased risk of ALL among daughters of overweight/obese mothers in early pregnancy (BMI ≥ 25 kg/m²; SIR = 1.4, 95% CI: 1.2–1.6) compared with the risk in daughters of mothers with a normal BMI. This association was not found in sons (SIR = 1.0, 95% CI: 0.9–1.1). Similar results were found for the association between ALL and maternal BMI before delivery. We did not find an association between low or high GWG and risk of ALL (both SIRs = 1.0, 95% CI: 0.9–1.1) in either male or female offspring. Our findings suggest that maternal overweight or obesity is an important risk factor for childhood ALL in daughters, whereas GWG is not associated with an increased risk of ALL. Further research on this mother-daughter association may shed light on a possible sex hormone/chromosome-related etiology of ALL.