All patients were stratified according to the Bologna criteria for poor ovarian response. Poor responders were classified with at least two of the three following criteria: (I) advanced maternal age (≥40 years) or any other risk factor for POR; (II) a previous POR(≤3 oocytes with a conventional ovarian stimulation protocol); and (III) an abnormal ovarian reserve test (ORT): antral follicle count (AFC) < 5-7 or serum anti-Mullerian hormone (AMH) <0.5-1.1 ng/mL, as described by the Bologna criteria