To analyze if oocytes can be obtained in all patients before cancer treatment within 2 weeks by initiating ovarian stimulation during the follicular or luteal phase.Prospective controlled multicenter trial.Four university-based centers.Forty cancer patients before chemotherapy.Twenty-eight patients were stimulated with gonadotropins in the follicular phase (group I). In 12 patients (group II), ovarian stimulation was initiated in the luteal phase, and these received GnRH antagonists and recombinant FSH. In 14 patients, 143 oocytes were further processed for fertilization by intracytoplasmic sperm injection (ICSI).Number of oocytes aspirated after ovarian stimulation, cumulative FSH/hMG dosage, viability and maturity of oocytes, and fertilization rate by ICSI.Patients in group I (age 27.6 ± 4.9 yrs) were stimulated on average for 10.6 days, and patients in group II (age 31.2 ± 5.7 yrs) for 11.4 days. Total amount of FSH was on average 2,255 IU (I) and 2,720 IU (II) per patient. Average and median numbers of aspirated oocytes were, respectively, 13.1 and 11.5 (I) versus 10.0 and 8.5 (II); 83.7% (I) and 80.4% (II) of the oocytes were mature and viable and could be treated by ICSI. Fertilization rate was 61.0% (I) versus 75.6% (II).This pilot study suggests that oocytes can be obtained before cancer treatment efficiently irrespective of the phase of the menstrual cycle.
