title: In vitro fertilization is associated with an increased risk of borderline ovarian tumours.
abstract: OBJECTIVE
  To compare the risk of borderline ovarian tumours in women having in vitro fertilization (IVF) with women diagnosed with infertility but not having IVF.
  
  
  METHODS
  This was a whole-population cohort study of women aged 20-44 years seeking hospital infertility treatment or investigation in Western Australia in 1982-2002. Using Cox regression, we examined the effects of IVF treatment and potential confounders on the rate of borderline ovarian tumours. Potential confounders included parity, age, calendar year, socio-economic status, infertility diagnoses including pelvic inflammatory disorders and endometriosis and surgical procedures including hysterectomy and tubal ligation.
  
  
  RESULTS
  Women undergoing IVF had an increased rate of borderline ovarian tumours with a hazard ratio (HR) of 2.46 (95% confidence interval [CI] 1.20-5.04). Unlike invasive epithelial ovarian cancer, neither birth (HR 0.89; 95% CI 0.43-1.88) nor hysterectomy (1.02; 0.24-4.37) nor sterilization (1.48; 0.63-3.48) appeared protective and the rate was not increased in women with a diagnosis of endometriosis (HR 0.31; 95% CI 0.04-2.29).
  
  
  CONCLUSIONS
  Women undergoing IVF treatment are at increased risk of being diagnosed with borderline ovarian tumours. Risk factors for borderline ovarian tumours appear different from those for invasive ovarian cancer.
authors: School of Population Health, Faculty of Medicine, Dentistry and Health Sciences, The University of Western Australia, M431, 35 Stirling Highway, Crawley, WA 6009, Australia. louise.stewart@uwa.edu.au
authors: Louise M
authors: LM
authors: Stewart
authors: C D'Arcy J
authors: CD
authors: Holman
authors: Judith C
authors: JC
authors: Finn
authors: David B
authors: DB
authors: Preen
authors: Roger
authors: R
authors: Hart
mesh_terms: D000328:Adult; D000077216:Carcinoma, Ovarian Epithelial; D005260:Female; D005307:Fertilization in Vitro / Q000009:adverse effects*; D005500:Follow-Up Studies; D006801:Humans; D007247:Infertility, Female / Q000150:complications / Q000628:therapy*; D009375:Neoplasms, Glandular and Epithelial / Q000209:etiology*; D010051:Ovarian Neoplasms / Q000209:etiology*; D016016:Proportional Hazards Models; D012307:Risk Factors