Serum dioxins, polychlorinated biphenyls, and endometriosis: a case-control study in Atlanta

Endometriosis among women of reproductive age can result in pain and infertility. The objectives of this study were to test if there is a relation between endometriosis and serum dioxin concentrations as expressed by total toxic equivalence and serum total polychlorinated biphenyl concentrations among women patients at one Atlanta reproductive medicine clinic during 1998-1999; a secondary objective was to provide exposure data for individual congeners of these chemicals and 1,1-dichloro-2,2-bis(4-chlorophenyl)ethane (p,p'-DDE) in women in Atlanta. Laparoscopy including biopsy and visualization of the peritoneal cavity, ovaries, outside of the fallopian tubes and uterus confirmed all endometriosis cases (n=60) and confirmed 30 controls without endometriosis. Other controls had an infertile partner (n=27) or ovulation problems (n=7) with no signs or symptoms of endometriosis. All serum samples were analyzed at the U.S. Centers for Disease Control and Prevention in 2003. Statistical analyses included Fisher's exact chi-square tests and logistic regression. Models were presented for the full study sample and for the subset that included all cases (n=60) and only controls (n=30) with surgical confirmation of disease-free status. Serum concentrations (lipid-adjusted and non lipid-adjusted) of analyzed exposure measures were low and similar for cases and controls and did not explain endometriosis in the study population.