Prescription medication use during pregnancy and risk of infant leukemia (United States).

Objective: We explored whether maternal medication use during pregnancy may be an important etiologic area for investigation in studies of infant leukemia.
Methods: In this case-control study, associations were explored between specific medications as recorded in the medical records of 243 mothers of infants who were diagnosed with leukemia at < 18 months of age and 393 mothers ol infants without leukemia identified through random digit dialing. Cases included 157 acute lymphoblastic (ALL), 77 acute myeloid (AML), and nine other leukemias. A total of 27 different drugs that were prescribed for at least six women were analyzed.
Results: Overall, non-statistically significant negative associations (Odds ratios, OR < 0.5) were observed with amoxicillin, nystatin, clomiphene, levothyroxine, cefaclor, and trimethobenzamide HCL. When cases were restricted to either myeloid or lymphoblastic leukemia, cotrimoxazole was prescribed for five ALL case mothers and no matched controls; no association with cotrimoxazole was observed with AML.
Conclusions: Given the number of comparisons, chance cannot be ruled out for any of the associations found here. However, a strength of this study is the lack of recall bias. The disparate data observed between AML and ALL in some instances may indicate areas of interest; they will be explored further in a case-control study of infant leukemia that is currently underway.