PHYSIOLOGICAL ESTRADIOL AND PROGESTERONE REPLACEMENT CYCLES IN WOMEN WITH OVARIAN FAILURE - A MODEL TO STUDY ENDOMETRIAL MATURATION AND SEXSTEROID-RECEPTOR REGULATION BY EXOGENOUS HORMONES

High endometrial receptivity has been achieved with physiological oest radiol and progesterone replacement cycles in women with ovarian failu re. To understand whether different protocols using the oral route or the transdermal route can influence the endometrial maturation and the regulation of sex steroid receptors, we studied 33 women with ovarian failure treated by two commonly used protocols and assessed endometri al receptivity using light microscopy, scanning electron microscopy an d immunohistochemistry for oestrogen and progesterone receptors on bio psies taken to include different periods of the luteal phase. The morp hology in these patients was similar to that observed in women with no rmal ovulatory cycles, indicating that the morphological response is n ot dependent on the type of oestradiol, oral or transdermal, in the re placement cycles as compared to the endogenous oestradiol in the menst rual cycle. The relative distribution of steroid receptors between the epithelium and stroma varies similarly to that observed during the lu teal phase of the menstrual cycle. These results confirm the role of p rogesterone, especially the importance of the number of days of exposu re to it; in the disappearance of steroid receptors from endometrial g lands. These observations give a better understanding of endometrial r eceptivity around the time of presumed implantation and confirm clinic al results concerning the best timing of oocyte transfer.