Many cancers are diagnosed in young women who have not had children. It is important to offer fertility preserving options to women recently diagnosed with cancer since many cancer treatments may result in premature menopause or infertility. Embryo cryopreservation (freezing) in humans has been available since the mid 1980’s and during the years since the first clinical use of this technology we have seen significant improvements in embryo survival and live birth rates. Egg freezing is technically more difficult to perform and until recently survival rates have been poor. However, we are now able to freeze human eggs with excellent future prospects for successful pregnancies, and many infertility clinics are now able to offer this technique.
One of the important concerns involved with either embryo or egg cryopreservation is that these techniques require stimulation of the ovaries to be effective treatments. Stimulation of the ovaries is important so that multiple eggs may be removed, improving the prospects for a successful pregnancy in the future. In the past it was assumed that it would be necessary to await a menstrual period before the stimulation could be started. This approach often led to significant delays before patients could have their eggs removed and move on to cancer treatment. We have learned that ovarian stimulations may be started at any time in the cycle through the use of medications called GnRH antagonists in conjunction with the pituitary hormones usually used to stimulate the ovary to produce multiple eggs. This approach allows us to quickly get eggs to maturation and removal, preventing any delay in cancer treatment.
Since breast cancer as well as other female cancers may be accelerated by high estrogen levels, it is important to offer treatments which minimize the estrogen elevation which usually occurs in preparation for removal of eggs. This can be accomplished through the selection of stimulating medications which minimize estrogen elevation. Two specific types of medication which accomplish this goal are gonadotropin releasing hormone antagonists, and anti-estrogen medications called aromatase inhibitors. In recent years we have gained substantial experience in the use of these medications and may now use this experience to reduce the estrogen related risks of fertility preservation. Medication protocols available today enable us to stimulate the ovaries quickly and efficiently with minimal estrogen elevation and no significant delay in planned cancer treatment. Patients preparing to undergo cancer treatment should find great comfort in the knowing that their fertility has been safely preserved with no additional risk to them.