Maternal pregnancy loss, birth characteristics, and childhood leukemia (United States).

OBJECTIVE

The authors evaluated the relation between maternal pregnancy loss, birth characteristics, and childhood leukemia in the Northern California Childhood Leukemia Study.

METHODS

Incident cases of childhood leukemia (age 0-14 years) were rapidly ascertained, and controls were randomly selected from birth records and individually matched to cases. A total of 366 cases [313 acute lymphoblastic leukemia (ALL) and 53 acute myeloid leukemia (AML)] and 460 controls were included in this analysis. The biological mothers of all subjects provided detailed reproductive history and birth characteristics of the index children during a personal interview. Odds ratio (OR) and 95% confidence intervals (CI) were estimated using conditional logistic regression. Data on maternal pregnancy loss and birth characteristics were also available from the birth certificates of 96.3% of all subjects.

RESULTS

History of miscarriage was associated with a significantly increased risk of AML (OR = 2.94, 95% CI: 1.03, 8.34), but not ALL. Neither birth weight, birth order, or parental ages appeared to be an important predictor of the risk of ALL or AML. A comparison between data from two different sources (interview versus birth certificate) indicated good reproducibility and offered some evidence against recall bias.

CONCLUSION

Maternal history of miscarriage is associated with an increased risk of childhood AML.