Related Experiment Video
Updated: May 8, 2026
Fertility Preservation Through Oocyte Vitrification: Clinical and Laboratory Perspectives
Published on: September 16, 2021
Effective method for emergency fertility preservation: random-start controlled ovarian stimulation
Hakan Cakmak1, Audra Katz, Marcelle I Cedars
1Division of Reproductive Endocrinology and Infertility, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, California.
Objective:
To determine whether random-start controlled ovarian stimulation (COS), in which a patient is stimulated on presentation regardless of her menstrual-cycle phase, has outcomes similar to conventional early follicular phase-start COS for fertility preservation in cancer patients.
Design:
Retrospective cohort study.
Setting:
Academic medical center.
Patient(S):
Women recently diagnosed with cancer and in preparation for gonadotoxic therapy.
Intervention(S):
Random- versus conventional-start COS.
Primary Outcome:
number of mature oocytes retrieved; secondary outcomes: pattern of follicular development, oocyte yield, and fertilization rate.
Result(S):
The number of total and mature oocytes retrieved, oocyte maturity rate, mature oocyte yield, and fertilization rates were similar in random- (n = 35) and conventional-start (n = 93) COS cycles. No superiority was noted when comparing COS started in the late follicular (n = 13) or luteal phase (n = 22). The addition of letrozole, in the case of estrogen-sensitive cancers, did not adversely affect COS outcomes or oocyte maturity and competence in either random- or conventional-start protocols.
Conclusion(S):
Random-start COS is as effective as conventional-start COS in fertility preservation. This protocol would minimize delays and allow more patients to undergo fertility preservation and still proceed with cancer treatment within 2-3 weeks.
