In general, for women with cancer, controlled ovarian stimulation (COS) for embryo or oocyte cryopreservation is similar to IVF for infertile couples. However, there are some additonal considerations in this population:

What is the general protocol for COS?

Pre-cycle considerations 

  • Ovarian reserve testing. A study by Anderson et al. found that pretreatment serum AMH, FSH antral follicle counts, and age predict the chance of premature menopause 4-5 years after breast cancer treatments1.
  • Semen analysis (when applicable)
  • FDA-required infectious disease labs.  Consider having the couple undergo testing as if they will be ‘donors’ in the future, completing appropriate ‘donor’ questionnaires and having their labs completed at an FDA-approved site. 


  • Medications are used to attempt to have the ovaries produce a cohort of multiple oocytes.  Several stimulation protocols and medications are available and have their own pros and cons. 
  • These medications generally start soon after the woman’s menstrual cycle starts, and are used daily for approximately 8-12 days. 

General Protocol Information

  • Once the stimulation medications start, the woman will have approximately 5 visits with ultrasounds and blood draws to monitor follicular growth.
  • When the cohort of follicles is thought to likely include mostly ‘mature oocytes’, a final trigger shot is used to allow the final maturation of the oocytes.  This can be done with HCG or GnRH-agonist.
  • The egg retrieval occurs approximately 34-36 hours after the trigger shot.  This is a transvaginal ultrasound guided aspiration of oocytes, usually while the woman is sedated.
  • If the woman is planning to freeze oocytes, they likely will be frozen the day of the egg retrieval.
  • If the woman is planning to freeze embryos, the eggs will be fertilized in the embryology lab.  This can be done with “conventional fertilization” or with ICSI (intra-cytoplasmic sperm injection), depending on the quality of the sperm.


  • Embryos can be frozen on day 2, 3 or 5.  No standard of care exists about which day to freeze.    
  • The number of oocytes or embryos frozen in each vial should be carefully considered, based on:
    • The patient's age
    • Quality of the embryo or oocytes
    • Patient wishes
    • The individual clinic's prior success with frozen embryos or oocytes

Some additional considerations for COS in cancer patients:


  • Safety
    • Is COS safe in women with cancer?
    • Is COS safe in women with hormone-sensitive cancers?



1. Anderson RA, Cameron DA. Pretreatment serum anti-mullerian hormone predicts long-term ovarian function and bone mass after chemotherapy for early breast cancer. J Clin Endocrinol Metab, 2011 May;96 (5): 1336-43.

2. Grifo JA, Noyes N. Delivery rate using cryopreserved oocytes is comparable to conventional in vitro fertilization using fresh oocytes: potential fertility preservation for female cancer patients. Fertili Steril, 2010 Feb; 93 (2):391-6.

About the Author

Jennifer Mersereau, MD, MSCI, is an reproductive endocrinologist in the University of North Carolina's Department of Obstetrics and Gynecology. As the Director of the Fertility Preservation Program, she has extensive experience guiding patients and physicians through the oncofertility experience. 

This page was last updated March 14, 2012.