MID TO LATE LUTEAL-PHASE STEROIDS IN MINIMAL STAGE ENDOMETRIOSIS AND UNEXPLAINED INFERTILITY

Serum and peritoneal fluid concentrations of progesterone and 17 beta- oestradiol were measured during days 20-27 of the luteal phase in 33 w omen with minimal stage endometriosis and 21 with unexplained infertil ity. The results were analysed using Student's t-test and straight lin e regression analysis. In both groups, 17 beta-oestradiol and progeste rone values were several-fold higher than the corresponding serum valu es and there were significant correlations between the peritoneal flui d and the serum steroid values. In the peritoneal fluid there was a si gnificant reduction in both progesterone and its ratio with 17 beta-oe stradiol in women with minimal stage endometriosis (P < 0.03, P < 0.04 , respectively). The peritoneal fluid levels of 17 beta-oestradiol in women with minimal stage endometriosis were, however, not significantl y altered. Despite the correlations between peritoneal fluid and serum steroid levels, there were no significant changes in the serum concen trations of progesterone, 17 beta-oestradiol or the ratio of progester one to 17 beta-oestradiol in women with minimal stage endometriosis. I t is concluded that luteal phase progesterone and its relationship to 17 beta-oestradiol are subtly altered in infertile women with minimal stage endometriosis compared with women with unexplained infertility. These alterations may be more clearly demonstrated in peritoneal fluid rather than in peripheral blood, possibly because the latter contains steroids which are of non-ovarian origin and are also constantly affe cted by the liver enzyme activity and enterohepatic circulation of ind ividual subjects.