The impact of luteal phase support on endometrial estrogen and progesterone receptor expression: a randomized control trial

A prospective, randomized study was conducted in women undergoing controlled ovarian hyperstimulation for oocyte donation. Participants were randomized to receive no luteal support, vaginal progesterone alone, or vaginal progesterone plus orally administered 17 Beta estradiol. Endometrial biopsies were obtained at 4 time points in the luteal phase and evaluated by tissue microarray for expression of ER alpha and PR-B.One-hundred and eight endometrial tissue samples were obtained from 12 patients. No differences were found in expression of ER alpha and PR-B among all the specimens with the exception of one sample value.The administration of progesterone during the luteal phase of COH for oocyte donor cycles, either with or without estrogen, does not significantly affect the endometrial expression of ER alpha and PR.The spatial and temporal expression of specific extracellular matrix (ECM) proteins and adhesion molecule genes creates a profile that is crucial for successful embryo implantation [1,2]. The effect of exogenous hormone administration on these complex hormonal signaling pathways is not totally elucidated. Some investigators purport that controlled ovarian hyperstimulation (COH) protocols inevitably lead to lack of synchrony between the development and maturation of the endometrium and the time of oocyte retrieval or "ovulation" [3,4]. However, conflicting information exists as to whether COH does in fact lead to a clinically significant degree of endometrial lack of synchrony [5-8].Ovarian stimulation protocols for IVF have been frequently associated with luteal phase deficiency and poor implantation rates [3,4]. Additionally, there are some data showing that, in GnRH agonist/HMG stimulated cycles, lack of supplementation with exogenous progesterone (P) results in impaired P bioavailability [9,10]. For this reason, luteal phase support is customarily used to improve endometrial structure and histology thus facilitating the implantation process. P is accept