OVULATION INHIBITION WITH HUMAN CHORIONIC GONADOTROPHIN

Abstract

ABSTRACT Eight women with regular menstrual cycles were treated daily during 9 cycles with HCG (Human Chorionic Gonadotrophin) 3000 or 5000 IU daily for a period of 4–7 days. This treatment was started between the 1st and the 6th day after the onset of menstruation. Control of the treatment cycles was performed by basal body temperature, pregnanediol serial estimations, endometrial biopsies and in addition in 5 treatment cycles by radio-immunological assay of oestradiol-17β (Oe2), progesterone, LH and FSH from the serum at intervals of 1 to 3 days. In 6 of these cycles where treatment started on the 4th day or later, ovulation was inhibited (2 cycles) or postponed (4 cycles) to the 24th–46th day. In these 6 treatment cycles the progesterone and pregnanediol increase during HCG treatment was poor or absent. The typical Oe2 increase of the normal menstrual cycle was impaired. In the 3 remaining cycles where treatment was started on the 1st, 2nd and 4th day, we observed during HCG treatment increases in Oe2 and progesterone serum values similar to that found during corpus luteum activity, and menstruation from a secretory endometrium between the 13th–19th day of the cycle. The histologically examined ovaries of one woman who was treated with HCG from the 2nd to the 6th day of the cycle showed distinct Iuteinization of the theca interna of all tertiary follicles and a beginning degeneration of the granulosa. These findings give support to the hypothesis that the luteinization of the theca interna leads to degeneration of the tertiary follicles thereby causing ovulation inhibition or postponement of ovulation.