title: Examination of gender effect in birth weight and miscarriage associations with childhood cancer (United Kingdom).
abstract: BACKGROUND
  Higher birth weight and maternal history of miscarriage has been associated with an increased risk of childhood leukemia. The possibility that this association may be sex-specific has not been explored in detail in previous studies.
  
  
  METHODS
  In a retrospective case-control study, 732 childhood (< or =14 years) cancer cases from a population-based Registry in Northern England whose hospital birth records could be accessed and 3,723 controls matched for date and hospital of birth to the cases were compared. We examined birth weight for sex-specific associations with childhood cancer. Conditional logistic regression analysis was used for statistical evaluation of associations.
  
  
  RESULTS
  In acute lymphoblastic leukemia (ALL) (225 cases and 1,163 matched controls), birth weight and sex showed a strong interaction (P = 0.003). In boys with ALL, but not in girls, there was a nonlinear association with birth weight (P for trend = 0.008; OR = 3.05 for the highest quintile compared to the second lowest quintile, 95% CI = 1.40-6.64; P = 0.005). When birth weights were adjusted using UK standards for gestational age and sex, the risk associations were similar in statistical significance and magnitude. Maternal history of miscarriage showed an association with all cancers and individually with ALL. The miscarriage association with ALL was statistically significant in boys only (OR = 1.91, 95% CI = 1.07-3.42; P = 0.03). A multivariable model for ALL containing other examined maternal and reproductive variables confirmed the independence of the birth weight and miscarriage associations. There was no birth weight or miscarriage associations in other cancers.
  
  
  CONCLUSIONS
  This study confirmed the risk associations with birth weight and miscarriages in childhood ALL. Statistically significant association of size at birth suggested marked differences in etiology between girls and boys.
authors.affiliation: Paediatric and Lifecourse Epidemiology Research Group, Sir James Spence Institute, School of Clinical Medical Sciences, Newcastle University, Newcastle-upon-Tyne, UK. tevfik.dorak@newcastle.ac.uk
authors.forename: M Tevfik
authors.initials: MT
authors.lastname: Dorak
authors.forename: Mark S
authors.initials: MS
authors.lastname: Pearce
authors.forename: Donna M
authors.initials: DM
authors.lastname: Hammal
authors.forename: Richard J Q
authors.initials: RJ
authors.lastname: McNally
authors.forename: Louise
authors.initials: L
authors.lastname: Parker
mesh_terms: D000026:Abortion, Habitual / Q000453:epidemiology*; D000293:Adolescent; D001724:Birth Weight; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D016017:Odds Ratio; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000453:epidemiology*; D011247:Pregnancy; D012189:Retrospective Studies; D012306:Risk; D012737:Sex Factors; D006113:United Kingdom / Q000453:epidemiology