Evaluation of the Phthalate Esters in South Indian Women with Endometriosis

Background: To evaluate the possible association between phthalate esters (PEs) and the occurrence of endometriosis. Blood samples were collected from 99 infertile women with endometriosis (study group); 135 age-matched women without endometriosis (control group) but with infertility related to tubal defects, fibroids, polycystic ovaries, idiopathic infertility and pelvic inflammatory diseases diagnosed by laparoscopy with no evidence of endometriosis or other gynecological disorders during laparoscopic sterilization. Materials and Methods: This is a prospective case-control study, which recruited women undergoing infertility treatment at three collaborating centers (BMMHRC: Bhagwan Mahavir Medical Hospital and Research Centre, MHRT: Maternal Health and Research Trust, and Owaisi Hospital and Research Center) of Reproductive Medicine Hyderabad, which receives cases from all over the region of Andhra Pradesh, India. The concentrations of Phthalate Esters were measured by using the High Performance Liquid Chromatography (HPLC). Evaluation of Phthalate Esters concentrations in women with endometriosis compared with women who are free from the disease. Results: Women with endometriosis showed significantly higher concentrations of Phthalate esters (Dimethyl phthalate (DMP), Diethyl phthalate (DEP), Di-n-butyl phthalate (DnBP), Butyl benzyl phthalate (BBP) and Bis (2-ethylhexyl) phthalate (BEHP)) compared with control group. We found that (38%) of the cases with endometriosis and (21%) of the control group. The correlation between the concentrations of Phthalate esters and different severity of endometriosis was strong and statistically significant at p < 0.05 for all five compounds (DMP): r=+0.57, p < 0.0001; DnBP r=+0.39, p < 0.0001; BBP: r=+0.89, p < 0.0001; DnOP: r=+0.66, p < 0.0001 and BEHP: r=+0.33, p < 0.0014. Conclusion: This study for the first time from Indian subcontinent demonstrates that possibly Phthalate Esters might have a role in etiology of endometriosis.