Received February 03, 2007
Accepted June 02, 2007

Among the possible mild stimulation protocols, the natural cycle offers many advantages. Natural cycles have been proposed as an alternative to simplify in-vitro fertilization (IVF) treatment procedures, to reduce its costs, and to avoid the risks of ovarian hyperstimulation and multiple pregnancies. Improvements in laboratory techniques and methods of follicle aspiration have created a renewed interest in natural cycle IVFET and turned into a viable option. Objective: The objective of this study was to assess the reproductive competence of oocytes obtained by follicular flushing in poor responders patients. Design: Prospective comparative study. Patients and Methods: 165 infertile IVF-ET candidates. We studied 271 consecutive mono-follicular IVF-ET cycles. Oocyte pickup (OPU) was performed 34 hours after hCG administration, oocytes were allocated in two groups according to its retrieval method: oocytes obtained in the first follicular aspiration (group FA, n=127); and oocytes retrieved in the subsequent follicular flushing (group FF, n=102).Main outcome measure: Clinical pregnancy and embryo implantation rates. Results: Patients’ characteristics, fertilization rates, and clinical pregnancy rates/oocyte were comparable in both of groups. In contrast, embryo morphology (41% vs. 59%, P<0.01) and implantation rates (20.4% vs. 34.8%, P<0.04) were better in the group FF. Conclusions: An optimal reproductive competence was observed on oocytes retrieved by follicular flushing in poor responders patients.