Peritoneal fluid prostaglandins in various stages of the menstrual cycle: role in infertile patients with endometriosis.

Thirty-nine patients with pelvic endometriosis and 45 patients with no evidence of endometriosis were entered in this study. The mean age was 29 years for each group. The volume of peritoneal fluid showed an increase towards the end of the cycle in both groups. Although the volume was higher in the endometriosis group than the control group, the difference between them was not significant. The concentration of prostaglandins F2 alpha and E2 was higher in patients with endometriosis than in the control group. The difference was significant (P less than 0.05) during days 9-16 and 17-24 for both prostaglandins, and during days 1-8 for prostaglandin F 2 alpha only. The high concentration of prostaglandins in the periovulatory and early luteal phases of the cycle may have adverse effects on tubo-ovarian function in endometriosis patients. Prostaglandin studies in peritoneal fluid are of significance during days 9-24 of the cycle when the effect of regurgitated menstrual fluid in the early phase of days 1-8 may be avoided.