Higher Maternal BMI in Pregnancy Associated with Childhood Acute Lymphoblastic Leukemia Risk in Daughters: Study
Germany: A recent study published in the Leukemia Journal suggests that higher maternal body mass index (BMI) during pregnancy may increase the risk of childhood acute lymphoblastic leukemia (ALL) in female offspring but not in male offspring.
Mahdi Fallah, German Cancer Research Center (DKFZ), Heidelberg, Germany, and colleagues analyzed data from over 2.9 million children born in Sweden between 1983 and 2018, making it one of the largest population-based cohort studies to explore this association.
They found that both higher maternal BMI in early pregnancy and before delivery were linked to an increased risk of childhood ALL in female offspring. However, no such associations were observed in male offspring, and gestational weight gain did not appear to influence the risk of ALL in either sex.
The study evaluated 2,961,435 children, among whom 1,388 were diagnosed with ALL during follow-up, including 772 boys (55.6%) and 616 girls (44.4%). The maternal BMI distribution showed that 64.6% of children were born to mothers of normal weight (BMI 18.5-24.9 kg/m2), 22.4% to overweight mothers (BMI 25-29.9 kg/m2), 9.5% to obese mothers (BMI ≥30 kg/m2), and 3.6% to underweight mothers (BMI <18.5 kg/m2).
Key Findings:
- Children born to mothers with a BMI of 25 kg/m2 or higher in early pregnancy had a greater likelihood of being diagnosed with ALL compared to those born to mothers of normal weight (SIR, 1.2).
- There was no significant association between maternal underweight status in early pregnancy and childhood ALL (SIR, 1.1).
- Sons of overweight or obese mothers did not show an increased risk of ALL (SIR, 1.0).
- Daughters born to mothers with a BMI of 25 kg/m2 or higher in early pregnancy had a 40% greater risk of ALL compared to those born to mothers of normal weight (SIR, 1.4).
- Girls born to mothers with a BMI of 29 kg/m2 or higher before delivery had an increased risk of ALL compared to those born to mothers with a BMI of 22.5-28 kg/m2 (SIR, 1.4), while there was no such association in boys (SIR, 0.9).
- Analysis of gestational weight gain in 1,463,141 children revealed no significant difference in ALL risk between children born to mothers with high (SIR, 1.0) or low gestational weight gain (SIR, 1.0) compared to those with normal weight gain.
The researchers emphasized that this is the first study to highlight a sex-specific difference in the association between maternal BMI in early pregnancy and the risk of childhood ALL. They suggest that further research is needed to explore the potential role of sex hormones and chromosomal factors in this mother-daughter association.
Reference:
Liu, J., Kharazmi, E., Liang, Q., Chen, Y., Sundquist, J., Sundquist, K., & Fallah, M. (2025). Maternal weight during pregnancy and risk of childhood acute lymphoblastic leukemia in offspring. Leukemia, 1-9. https://doi.org/10.1038/s41375-025-02517-6
