title: Risk factors for pelvic endometriosis in women with pelvic pain or infertility. Gruppo Italiano per lo Studio dell' endometriosi.
abstract: OBJECTIVE
  The objective of the study was to analyse the relationship between selected characteristics and risk of pelvic endometriosis.
  
  
  METHODS
  Eligible for the study were 817 women with primary or secondary infertility or pelvic pain requiring laparoscopy. Of these, 393 were included for infertility and 424 for pelvic pain.
  
  
  RESULTS
  A total of 345 (42.2%) had a diagnosis of endometriosis and 472 did not have the disease. Multiparous women had endometriosis less frequently than nulliparous, the estimated odds ratios (OR) were respectively 0.9 (95% confidence interval, CI, 0.5-1.6) and 0.4 (95% CI 0.2-0.7) in women reporting one and two or more births. In comparison with women reporting no spontaneous abortion, the estimated OR was 0.3 (95% CI 0.2-0.5) in those who reported > or =1 miscarriage. In comparison with women reporting menstrual cycles lasting > or =25 days subjects with totally irregular menstrual cycles had a reduced risk of endometriosis (OR 0.6, 95% CI 0.3-0.9). No significant association emerged between smoking, age at menarche and risk of endometriosis.
  
  
  CONCLUSIONS
  this study confirms, with a different methodological approach to previously published studies, that multiparity, a history of abortion and lifelong irregular menstrual pattern decrease the risk of endometriosis in women with pelvic pain and infertility.
mesh_terms: D000328:Adult; D004715:Endometriosis / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000150:complications; D016013:Likelihood Functions; D016015:Logistic Models; D017699:Pelvic Pain / Q000150:complications; D017584:Reproductive History; D012307:Risk Factors