title: Association of early life factors and acute lymphoblastic leukaemia in childhood: historical cohort study.
abstract: In a historical cohort study of all singleton live births in Northern Ireland from 1971-86 (n=434,933) associations between early life factors and childhood acute lymphoblastic leukaemia were investigated. Multivariable analyses showed a positive association between high paternal age (> or =35 years) and acute lymphoblastic leukaemia (relative risk=1.49; 95% confidence interval (CI)=0.96--2.31) but no association with maternal age. High birth weight (> or =3500 g) was positively associated with acute lymphoblastic leukaemia (relative risk=1.66; 95% CI=1.18--2.33). Children of mothers with a previous miscarriage or increased gestation (> or =40 weeks) had reduced risks of ALL (respective relative risks=0.49; 95% CI=0.29--0.80, and 0.67; 95% CI=0.48--0.94). Children born into more crowded households (> or =1 person per room) had substantially lower risks than children born into less crowded homes with also some evidence of a lower risk for children born into homes with three adults (relative risks=0.56; 95% CI=0.35-0.91 and 0.58; 95% CI=0.21-1.61 respectively). These findings indicate that several early life factors, including living conditions in childhood and maternal miscarriage history, influence risk of acute lymphoblastic leukaemia in childhood.
authors.affiliation: Northern Ireland Cancer Registry, Department of Epidemiology and Public Health, The Queens University, Belfast, Riddel Hall, Stranmillis Road, Belfast BT9 5EE, UK. l.murray@qub.ac.uk
authors.forename: L
authors.initials: L
authors.lastname: Murray
authors.forename: P
authors.initials: P
authors.lastname: McCarron
authors.forename: K
authors.initials: K
authors.lastname: Bailie
authors.forename: R
authors.initials: R
authors.lastname: Middleton
authors.forename: G
authors.initials: G
authors.lastname: Davey Smith
authors.forename: S
authors.initials: S
authors.lastname: Dempsey
authors.forename: A
authors.initials: A
authors.lastname: McCarthy
authors.forename: A
authors.initials: A
authors.lastname: Gavin
mesh_terms: D000022:Abortion, Spontaneous; D000293:Adolescent; D000328:Adult; D001722:Birth Order; D001724:Birth Weight; D001942:Breast Feeding; D002648:Child; D015331:Cohort Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D008423:Maternal Age; D015999:Multivariate Analysis; D009660:Northern Ireland / Q000453:epidemiology; D009679:Nuclear Family; D010331:Paternal Age; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000453:epidemiology* / Q000209:etiology; D011247:Pregnancy; D012306:Risk; D012737:Sex Factors; D012923:Social Class