Double ovarian stimulation (DuoStim) protocol for fertility preservation in female oncology patients.

This article describes a revised ovarian stimulation protocol (DuoStim) for fertility preservation in female oncology patients which aims to maximise the number of gametes obtained with subsequent improvement in cumulative birth rate, without delaying cancer treatment. Ten patients diagnosed with malignancy between September 2014 and October 2015 were included. The patients were treated with the DuoStim protocol, undergoing two consecutive ovarian stimulation cycles and two oocyte retrievals. The primary outcome was the number of oocytes collected and vitrified during each oocyte retrieval and in total. The protocol was evaluated regarding medical risk and patients' feedback. During the first oocyte collection 81 oocytes (61 metaphase II) were retrieved (mean = 8.1; range = 1-13) and during the second oocyte collection 82 oocytes (67 metaphase II) were retrieved (mean= 8.2; range = 1-19). A total of 163 oocytes (128 metaphase II) were collected (mean = 16.3; range = 6-32) and cancer treatment was not delayed for any of these patients. There were no cases of ovarian hyperstimulation syndrome recorded. More patients and long-term follow-up is needed to assess the efficacy and safety of the DuoStim protocol. However, these early results are encouraging, demonstrating an increase in number of mature oocytes retrieved during ovarian stimulation for oncology patients, without delaying cancer treatment.