The role of mother's age in the risk of childhood leukemia.
D001722:Birth Order; D002675:Child, Preschool; D004314:Down Syndrome / Q000453:epidemiology; D005260:Female; D006506:Hepatitis A / Q000453:epidemiology; D006801:Humans; D007938:Leukemia / Q000453:epidemiology*; D008423:Maternal Age; D011051:Poliomyelitis / Q000453:epidemiology; D011247:Pregnancy; D013290:Streptococcal Infections / Q000453:epidemiology