Peritoneal macrophages and infertility: the association between cell number and pelvic pathology.

Increased numbers of peritoneal macrophages have been repeatedly associated with infertility. Because the factors contributing to this intraperitoneal exudate are unknown, this study was carried out to determine which anatomic or endocrinologic abnormalities in infertile women might be associated with an increase in leukocyte numbers. The peritoneal fluid from 103 women was analyzed. Nonparametric data analysis demonstrated significantly greater cell counts in infertile women with endometriosis, compared with other infertile women (P less than 0.01) or fertile control subjects (P less than 0.005). Multiple regression analysis was then used to determine the relationship of individual variables to cell number without the influence of confounding factors. These data demonstrate that the best correlation with elevated macrophage number is in women who have infertility and no mechanical fertility factors (of which mild endometriosis is a subgroup). Thus, an increase in peritoneal macrophage number is not restricted to women with endometriosis but, rather, is seen in a subset of infertile women generally without mechanical or endocrinologic infertility factors.