Analgesic use during pregnancy and risk of infant leukaemia: a Children's Oncology Group study.

<bold>Background: </bold>Infant leukaemia is likely initiated in utero.<bold>Methods: </bold>We examined whether analgesic use during pregnancy was associated with risk by completing telephone interviews of the mothers of 441 infant leukaemia cases and 323 frequency-matched controls, using unconditional logistic regression.<bold>Results: </bold>With the exception of a reduced risk for infant acute myeloid leukaemias with non-aspirin non-steroidal anti-inflammatory drugs (NSAID) use early in pregnancy (odds ratios=0.60; confidence intervals: 0.37-0.97), no statistically significant associations were observed for aspirin, non-aspirin NSAIDs, or acetaminophen use in early pregnancy or after knowledge of pregnancy.<bold>Conclusion: </bold>Overall, analgesic use during pregnancy was not significantly associated with the risk of infant leukaemia. [ABSTRACT FROM AUTHOR]