Abstract
OBJECTIVE: To study the clinical and logistical benefits of double ovarian stimulation (DuoStim) in egg donation. DESIGN: Prospective and observational study. SUBJECTS: Sixty healthy egg donors aged 18-35, all with regular menstrual cycles, normal karyotype, and adequate ovarian reserve. EXPOSURE: Each donor underwent two consecutive ovarian stimulations and oocyte retrievals within a single menstrual cycle, applying a standardized protocol. MAIN OUTCOME MEASURES: The primary outcome was the number of oocytes retrieved per stimulation. Secondary outcomes included blastulation rate, clinical pregnancy rate, implantation rate, and clinical miscarriage rate. RESULTS: The mean number of oocytes retrieved was significantly higher in the first stimulation compared with the second one (19.8 ± 2.0 vs. 13.3 ± 2.2). Similarly, the number of metaphase II oocytes was greater in the first stimulation (16.4 ± 1.8 vs. 11.5 ± 2.1). Despite the reduced oocyte yield, oocyte survival rates after vitrification were comparable between stimulations (91.8% follicular vs. 90.5% luteal). Usable blastocyst rates were also similar (42.8% vs. 49.1%), and clinical outcomes did not differ significantly: implantation rates were 69.8% (follicular) and 66.1% (luteal), and clinical pregnancy rates were 71.2% and 66.7%, respectively. The miscarriage rate was slightly lower in the follicular phase (7.7% vs. 12.4%), but this difference was not statistically significant. No cases of ovarian hyperstimulation syndrome or other serious adverse events were observed. CONCLUSIONS: DuoStim is a safe and efficient approach in egg donation, maximizing cycle efficiency and convenience by enabling two retrievals in a single cycle. Although the second stimulation yields fewer oocytes, oocyte and embryo quality remain unaffected. These findings support the use of DuoStim in donor programs, especially where time and resource optimization are priorities.