Risk factors for pelvic endometriosis in women with pelvic pain or infertility. Gruppo Italiano per lo Studio dell' endometriosi

OBJECTIVE:\n\nThe objective of the study was to analyse the relationship between selected characteristics and risk of pelvic endometriosis.\nSTUDY DESIGN:\n\nEligible 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.\nRESULTS:\n\nA 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.\nCONCLUSIONS:\n\nthis 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.