Immediate effect of prostaglandin F2alpha during the luteal phase of the menstrual cycle.

Serum luteinizing hormone, estradiol, 17-hydroxyprogesterone, and progesterone determinations were performed in five normally ovulating women prior to, during, and after prostaglandin F2alpha (PGF2alpha was infusion. A total of 75 mg of PGF2alpha was infused over 48 hours, beginning on the 4th day of the luteal phase. Endometrial biopsies were obtained at the completion of the infusion. In all patients, transient decreases in serum progesterone and 17-hydroxyprogesterone levels were observed during PGF2alpha infusion. Subsequent rises in the serum progesterone and 17-hydroxyprogesterone levels were observed 24 hours after completion of the infusion. There was no significant change in serum luteinizing hormone levels. Premature menstrual bleeding occurred with 24 to 72 hours after the termination of the infusion, while progesterone and 17-hydroxyprogesterone levels were still elevated. Endometrial histology revealed focal stromal necrosis in the presence of the normal secretory endometrium. It is concluded that, in the human, PGF2alpha at this dose and time schedule is not luteolytic.