Peritoneal fluid fractions from patients with endometriosis do not promote two-cell mouse embryo growth

Peritoneal fluid (PF) from 10 infertile patients with endometriosis, obtained during the follicular phase of the cycle during laparoscopy, did not promote two-cell mouse embryo growth to the extent observed by fluid obtained from seven normal controls. Five molecular weight (MW) fractions were obtained by ultrafiltration, and each was used as media supplement in the assay and compared with PF fractions from normal controls. All fractions of PF from patients with endometriosis inhibited mouse embryo growth to a greater extent than did normal controls. However, the MW fractions greater than 100,000 daltons showed greater inhibition of embryo development than did fractions less than 100,000 daltons. This study of cell-free PF suggests the presence of a humoral factor greater than 100,000 daltons that is inhibitory on mouse embryo growth.