title: Early-life factors and endometriosis risk.
abstract: OBJECTIVE
  To study early-life factors in relation to endometriosis risk in adulthood.
  
  
  METHODS
  Population-based case-control study.
  
  
  METHODS
  Integrated healthcare system.
  
  
  METHODS
  Cases (n = 310) were women diagnosed for the first time with endometriosis between the years 1996 and 2001, and controls (n = 727) were women without a diagnosis of endometriosis randomly selected from the healthcare system population.
  
  
  METHODS
  None.
  
  
  METHODS
  Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for the associations between intrauterine diethylstilbestrol (DES) exposure, maternal smoking, mother's age at delivery, firstborn status, birth weight, fetal number, prematurity, and regular soy formula feeding during infancy and endometriosis were estimated using unconditional logistic regression, adjusting for frequency matching and confounding variables. Information on early-life factors was ascertained retrospectively by in-person interview, with information on maternal DES use and regular soy formula feeding directly gathered from the participant's mother or other family member.
  
  
  RESULTS
  We observed that women who were regularly fed soy formula as infants had more than twice the risk of endometriosis compared with unexposed women (aOR 2.4, 95% CI 1.2-4.9). Our data also suggested increased endometriosis risk with prematurity (aOR 1.7, 95% CI 0.9-3.1) and maternal use of DES (OR 2.0, 95% CI 0.8-4.9, adjusting only for frequency matching variables), although these confidence intervals included the null.
  
  
  CONCLUSIONS
  Our results support the hypothesis that disruption of development during fetal and infant periods may increase the risk of endometriosis in adulthood.
authors.affiliation: Department of Epidemiology, School of Public Health, University of Washington, Seattle, Washington; Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington; Epidemiology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina. Electronic address: kristen.upson@nih.gov.
authors.forename: Kristen
authors.initials: K
authors.lastname: Upson
authors.affiliation: Department of Pediatrics, School of Medicine, University of Washington, Seattle, Washington; Department of Environmental and Occupational Health Sciences, School of Public Health, University of Washington, Seattle, Washington; Seattle Children's Research Institute, Seattle, Washington.
authors.forename: Sheela
authors.initials: S
authors.lastname: Sathyanarayana
authors.affiliation: Department of Epidemiology, School of Public Health, University of Washington, Seattle, Washington; Group Health Research Institute, Seattle, Washington.
authors.forename: Delia
authors.initials: D
authors.lastname: Scholes
authors.affiliation: Department of Epidemiology, School of Public Health, University of Washington, Seattle, Washington; Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington.
authors.forename: Victoria L
authors.initials: VL
authors.lastname: Holt
mesh_terms: D000293:Adolescent; D000328:Adult; D001724:Birth Weight / Q000502:physiology; D016022:Case-Control Studies; D004054:Diethylstilbestrol / Q000633:toxicity; D004715:Endometriosis / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008875:Middle Aged; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000453:epidemiology*; D012307:Risk Factors; D057566:Self Report; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D004054:Diethylstilbestrol
keywords: Population-based case–control study; early-life; endometriosis; soy formula