Endometrial microstructure after long-term use of a 91-day extended-cycle oral contraceptive regimen.

OBJECTIVE: To assess the effect on the endometrial microstructure of an extended-cycle oral contraceptive (OC) regimen containing ethinyl estradiol (EE) and levonorgestrel (LNG). METHODOLOGY: Subjects received up to four cycles of a 91-day extended-cycle OC regimen (84 consecutive days of monophasic 30 microg EE/150 microg LNG followed by 7 days of placebo). Endometrial biopsies were performed prior to the initiation and at the completion of therapy. All endometrial samples were processed centrally and reviewed by three independent pathologists blinded to treatment groups. RESULTS: Endometrial biopsies were performed in 50 women. In general, samples taken after completion of therapy with no further hormonal exposure demonstrated rapid return to normal endometrial cycling. In contrast, the majority of subjects still on active extended hormonal OC therapy at the time of biopsy had inactive or atrophic endometrium. No intravascular blood clots were observed in any of the specimens. CONCLUSION: The endometrial findings observed in this cohort of women treated with a 91-day extended-cycle OC regimen for up to 1 year showed no significant pathology. Additionally, the endometrium reverted quickly to normal cyclic changes in those subjects who, after completing therapy, elected not to continue with hormonal contraception.

Gene expression profiles and structural/functional features of the peri-implantation endometrium in natural and gonadotropin-stimulated cycles.

It has been speculated that controlled ovarian hyperstimulation (COH), as performed during in vitro fertilization therapy, may negatively affect embryo implantation. The objective of this prospective and randomized study was to investigate gene expression profiles of the human endometrium during the window of implantation of gonadotropin-stimulated COH cycles compared with temporally matched natural cycles (d 21). Analysis was performed with high-density oligonucleotide microarrays. In addition, other structural and functional features of the endometrium were investigated. Results corroborated that COH cycles depicted advancement of pinopodes appearance, histological features, and steroid receptor down-regulation when compared with natural cycles. These changes were associated with significant, albeit small, variations in gene expression (18 genes/expressed sequence tags and -1.55- to +3.40-fold changes). Second, there were significant changes in gene expression when comparing cycles using a GnRH agonist vs. a GnRH antagonist (13 genes/expressed sequence tags and +1.42- to +2.10-fold changes). This is the first attempt to elucidate gene expression profiles of the endometrium during COH cycles. The observed differences in gene expression in COH cycles using state-of-the-art protocols may not have a major functional impact on embryo implantation.