DATING THE ENDOMETRIAL BIOPSY BY FLOW-CYTOMETRY

Objective: To determine endometrial changes throughout the menstrual c ycle. Design: Flow cytometric analysis of endometrial cells versus chr onological dating. Setting: Women volunteers with a normal menstrual c ycle participated in this study that was done in an academic research environment. Patients: Two hundred thirty regular menstruating women w ith adequate luteal phase underwent endometrial biopsy at different da ys of their menstrual cycle; 138 biopsies were analyzed both histologi cally and by flow cytometry. Main Outcome Measure: Percentage of biops ies correctly classified in terms of chronological dating. Results: Fl ow cytometry correctly classified the chronological day of biopsies in 59% of cases, the proliferative versus secretory days in 91% of cases , and the early, mid, and late secretory phases of the menstrual cycle were correctly predicted in 86% of cases. Conclusion: Flow cytometry is a good method to determine growth and differentiation of the endome trium during the menstrual cycle. Detection of phases of the whole end ometrial cell population offer information on the biological adequacy of endometrial response to the biochemical environment.